March 1950
(Not for Publication)
HOP GRADE STUDIES
1949 Crop
Oregon Agricultural Experiment Station
in cooperation with
Grain Division, Production and Marketing
Administration, U.S.D.A.
by
J. D. SATHER, D. E. BULLIS and D. D. HILL
TABLE OF CONTENTS
Page
Introduction
1
Method of Study
2
Condition of Crop
3
Grades
6
Grading Results
8
Physical Analyses
13
Chemical Analysis
32
Relationship of Physical and Chemical Factors (Statistical)
38
Summary
65
INTRODUCTION I
The 1949 hop grading studies originated from a request of the United
States Brewers Foundation for the Production and Marketing Administration to
make such a study. The funds were appropriated jointly by the United States
Brewers Foundation and the Research and Marketing Administration.
The purpose of the study was to sample a cross section of the 1949 crop, to submit,
these samples to a detailed physical and chemical analysis, and to establish
the interrelationships between the physical and chemical factors.
Because of their years of experience and background in hop evaluation
research, the departments of Farm Crops and Agricultural Chemistry, Oregon
State College, were asked to do this work. The memorandum of agreement between the Production and Marketing Administration and the Oregon Agricultural
Experiment Station provided that the Department of Farm Crops would conduct
the physical analysis, the Department of Agricultural Chemistry would conduct
the chemical analysis and the two departments would analyze the data and interpret the results.
An attempt has been made to obtain fundamental information on the
quality of hops, on the measurement of certain factors that appear to indicate
quality, and on the relationships between them. No attempt is made to develop standards or to revise existing standards. However, attention is called
to weaknesses in existing tentative standards and to factors which should receive consideration in a grading system.
Because of the scope of the suggested work and because of the short
notice, the matter of personnel presented a serious problem. It was fortunate that the Department of Farm Crops was able to obtain the services of Mr.
J. D. Sather, former staff member, temporarily, that Mr. W. T. Wisbeck was
made available by the Portland district office of the Grain Products Branch,
Production and Marketing Administration) and that the Department of Agricultural Chemistry was able to obtain the services of Dr. S. C. Fang and Mrs.
Anna Naffs M.S., University of Kentucky. In addition) Mr. R. M, Magee,
Assistant Chemist, U.S.D.A., assisted in certain portions of the chemical
work.
Dr. Jerome Li and his staff from the Department of Mathematics, Oregon
State College; made most of the detailed statistical analyses contained in this
report.
2
METHOD OF STUDY
The samples were selected by the various state departments of agriculture and an effort was made to obtain a sample from every fourth lot that
was inspected for seed, stem and leaf in the state laboratories. This procedure was not always followed exactly, but Mr. W. T. Wisbeck kept in constant
touch with the state departments in order to promote this method of sampling
in so far as possible.
As the samples arrived in the Pacific Coast Headquarters, Grain Products
Branch supervision laboratory, they were given a laboratory number. The
samples were then divided in the Bates divider and one-half was used for the
supervision of seed, stem and leaf analysis. The remaining one-half was
divided and the one portion (1/)4) was sieved over a 30/64 round hole sieve.
The portion remaining on top of that sieve was considered as whole cones.
The protion through the sieve was considered as broken cones. These whole and
broken portions were placed in separate bags. The remaining one-fourth was
again divided and one-eighth was used for physical analysis. The other oneeighth and the whole and broken portions were sent to Oregon State College for
chemical analysis and moisture determination.
In addition to the standard analyses for seed, stem and leaf content,
all samples were given physical tests for broken cones, general appearance,
amount of lupulin, color and condition of lupulin, and damage. Methods of
making these determinations and their reliability have been presented in
previous reports to the Brewers Hop Research Institute.
The data on physical
analyses were then used to apply tentative hop standards developed previously.
The applications of these standards were then analyzed to indicate possible
weaknesses and inaccuracies which developed and to suggest possible changes.
After the chemical analyses (reported in a separate section of this report) had been completed, a statistical study to determine the relationships
with physical tests was undertaken. Many of these had been indicated by previous study. The number of samples involved and the extent to which they
represented the current crop make this study of more than ordinarrimportance.
Many of the relationships between physical and chemical factors are suspected
by those experienced in hops. However, when these are supported by sound
statistical data, it then becomes possible to use certain characters with
confidence in evaluating hop quality.
3
GENERAL IMPRESSIONS OF THE 1949 CROP
The general trend of the hop in 1949 was much better in some respects
than for any previous year that the inspector had been working on hops.
There
was far less discoloration and disease than normal. The crop was far from
normal as to maturity, however.
In Washington, Early Clusters were practically all harvested slightly immature. This resulted in a green color but a
lusterless hop and a lupulin which was off-color unless extreme care was used
in drying and handling.
This lack of luster is quite often referred to in the
trade as a "muddy" sample.
The Fuggles crop in Oregon, on the other hand, was mostly overmature
and had far less green color than normal. This hop had a bleached appearance
but had a more uniform color than normal.
The California crop was more nearly normal than Oregon Fuggles or
Washington Early Clusters but the Sacramento crop did not have quite as green
a color as usual. The_lupulin content was somewhat better than normal in the
Sacramento crop, indicating above normal maturity. The very rich hop characteristic of the Santa Rosa district crop was less in evidence than normal.
The Late Cluster hops in Oregon and Washington were nearly normal, but
showed much less discoloration and disease than encountered in any of the previous years viewed by the inspector.
The Idaho crop had a normal color but appeared unusually dry and broken.
The entire crop appeared to be quite uniforth and was neither very good nor very
bad.
A good many samples in all three states showed some mechanical damage.
This damage was thought to result largely from sack burn where the hops had
been piled up prior to drying and from improper drying.
This was reflected in
a number of samples with off-color lupulin as well as slightly off-color hops.
There has been a good deal of discussion in the industry about the
broken condition of the 1949 hop crop in all states.
It seems to be the
general opinion that the crop is much more broken than usual. Unfortunately,
we do not have a good comparison between the 1949 crop and other years.
However, a limited number of samples were analyzed for broken cones in 1947.
The results of these comparisons showed that Washington had about the same
percentage of whole cones in 1947 as in 1949. Oregon had about five percent
lower in 1949 than in 1947, while California was five percent higher in 1949
than in 1947. Idaho had no data for 1947 but the 1949 crop was very low in
the percentage of whole cones.
Since an examination of the samples submitted for this study seemed to
indicate that the hop crop was somewhat different than previously encountered,
it seemed desirable to visit growers and dealers in the hop area. A good many of
the prominent growers and dealers in Oregon and Washington were contacted to
determine if, in their opinion, this was a normal or average crop in 1949,
recognizing that their experience was greater and more varied than the investigators.
It is significant that everyone contacted in either state agreed.
that this crop was different than any they had ever seen.
All parties
contacted, however, did not agree that this crop was better.or worse. Some
4
thought one way and some the other way. The dealers agreed, in general, that
this was a much easier crop to market than any other crop they had handled.
They also generally agreed that extremely good or extremely bad hops were
quite scarce. In general, both growers and dealers seemed to think this was
better than an average crop. However, it was pointed out that the poor quality hops were not picked this year because of the marketing agreement and)
therefore, it would naturally be better than average with the extreme lo*
quality still on the vines,
5
HOP STANDARDS
Tentative standards for hops were developed by the U. S. Department of
Agriculture in 1943. These standards,which were based on information in the
hop grading studies of the Oregon Experiment Station and the Brewers Hop Re
search Institu%,were for study only. They were published in the Hop Grading
Report of 194304. Slight revisions were suggested in the 1946 report(2).
For purposes of study these standards have been applied to the 1949 samples.
The results of this grading and of the analyses which were made suggest that
certain revisions in the tentative hop standards are in order should they be
adopted for general use. Comments and suggestions for revisions of grades
made in connection with these studies are primarily for the consideration of
those agencies having the authority and responsibility for grade formation and
application.
The following tentative standards presented in a previous report are
included for reference only.
TENTATIVE UNITED STATES STANDARDS FOR HOPS
For the purposes of the tentative United States standards for hops:
Hops - Hops shall be the dried cones of the cultivated varieties of
Hops may not contain more than 20 percent of leaves and stems, which 20
may include not more than one percent of material other than'leaves and stems
of the hop plant.
hops.
Classes - Hops shall be divided into three classes as follows: Class
Clusters; Class II, Fuggles; and Class III, Miscellaneous. Hops in Class III
shall bear the varietal name.
Grades - Hops shall be graded and designated according to the respective
grade requirement of the numerical grade and sample grade of the appropriate
class, and according to the special grade when applicable.
Grade Designations
The grade designations shall include successively
the letters "U.S4rthe number or name of the principal grade, the name of the
class, and such additional statements as may be required by these standards.
(1)
Third Annual Report of Investigations to Develop Hop Grades.
Hill and Bullis, 1943.
(2)
Fourth Report of Investigations to Develop Hop Grades.
Hill, Bullis and Sather, 1946.
6
Grade Requirements for
the Classes Clusters, Fuggles, and Miscellaneous Hops
Condition and
General Appearance
Grade
U. S. No. 1
Maximum Limits of
Leaf and
Whole
Stem
Cones
e
%
/0
Excellent
5
70
U. S. No. 2
Good
8
55
U. S, No. 3
Fair
11
35
.
U. S. Sample
Grades
Of any one of these classes of hops which do not come within
the requirements of any of the grades of No. 1 to 3 inclusive,
or which have any aroma that is not typical of sound hops, or
which show evidence of being dried at an excessively high temperature, or which have been damaged by high or low moisture, or
which contain more than 14,5 percent of moisture, or which have
discolored or shrunken lupulin, or which contain more than 50
percent of cones that are discolored from mechanical means, or
which contain more than 5 percent of cones that are otherwise
damaged by disease or insects, or which are otherwise of distinctly
low quality.
SPECIAL GRADES FOR HOPS
Seedless Hops. Definition.
contain more than 3 percent seed.
Seedless hops shall be hops that do not
Grades. Seedless hops shall be graded and designated according to the
grade requirement of the standards applicable to such hops if they were not
seedless, and there shall be added to and made a part of the grade designation the word "seedless,"
Semi-seedless Hops. Definition. Semi-seedless hops shall be hops
that contain more than 3 percent but not more than 6 percent of seeds.
Grades. Semi-seedless hops shall be graded and designated according
to the grade requirements of the standards applicable to such hops if they
were not semi-seedless, and there shall be added to and made a part of the
grade designation the word "semi-seedless."
Fat Hops, Definition. Fat hops shall be hogs which have a lupulin
content materially in excess of normal or average lupulin content.
Grades. Fat hops shall be graded and designated according to the grade
requirements of the standards applicable to such hops if they were not fat hops,
and there shall be added to and made a part of grade designation the word "fat."
7
Thin Hops.
Definition. Thin hops shall be hops which have a lupulin
content of materially lower than the normal average lupulin content.
Grades. Thin hops shall be graded and designated according to the
grade requirements of the standards applicable to such hops if they were
not thin hops,and there shall be added to and made a part of the grade designation the word "thin,"
Tough Hops.
Definition. Tough hops shall be hops which contain more
than 11.5 percent but not more than 14.5 percent of moisture.
Grades.
Tough hops shall be graded and designated according to the
grade requirements of the standards applicable to such hops if they were not
tough, and there shall be added to and made a part of the grade designation
the word "tough."
DEFINITIONS
Basis of Grade Determination.
All determinations shall be made on the basis of the hops as a whole.
Percentages.
Percentages shall be percentages by weight.
Percent of Moisture.
Percentage of moisture shall be ascertained by the air-oven method
described in Methods of Analysis of the American Society of Brewing Chemists,
4th revised edition, 1944, or by a comparable method obtaining similar results.
Seed.
Seed shall include all hop seed regardless of maturity.
Leaves and Stems
Leaves and stems shall include all leaves and stems of the hop plant
except the stem "petioles" which bear the individual cones. Leaves and stems
may include not to exceed one percent of material other than leaves and stems
of the hop plant.
Whole Cones
Whole cones shall be the leaf-free hops which remain on top of the
30/64 round hole sieve.
Condition and General Appearance
The condition and general appearance of hops shall be considered to be
excellent or good or fair, which terms are defined as follows:
Excellent shall be hops that have a natural luster and a uniform
green or yellowish green core. Excellent hops may contain not more
than 10 percent of cones that are discolored from all causes, not more
8
than a trace of damage due to insects, disease, mechanical or maturity
damage, and shall be soft to the touch. The lupulin shall be sticky
and a uniform lemon-yellow color, and the individual particles shall
be angular in character.
Good shall be hops that fail to meet the condition and general
appearance requirements of excellent hops, or that have a yellow color.
Good hops may contain not more than 25 percent of cones that are discolored from all causes, or not more than two percent of cones that
are damaged due to disease, insects, mechanical means or maturity, or
lupulin that is light yellow in color. The lupulin in good hops need
not be angular.
Fair shall be hops that fail to meet the condition and general
appearance of either excellent or good hops, or that have a reddishyellow color. Fair hops may contain not more than 50 percent of cones
that are discolored from all causes, or not more than five percent of
cones that are damaged by insects, disease, maturity or mechanical
means. The lupulin may be dark yellow in color and need not be
angular.
RESULTS OF GRADING
Oregon, 176 Samples
U. S. No. 1
1 sample
U. S. No. 2 -- 7 samples
4 graded down on whole cones.
3 graded down on whole cones and general appearance.
U. S. No. 3 -- 69 samples
64 graded down on whole cones.
1 graded down on whole cones and general appearance.
1 graded down on whole cones and leaf and stem.
3 graded down on leaf and stem.
U. S. Sample Grade -- 99 samples
95 graded down on whole cones.
3 graded down on whole cones and leaf and stem.
1 graded down on leaf and stem.
By eliminating whole cones as a grading factor the grades would be as
follows:
U. S. No. 1 -- 21 samples
9
U. S. No. 2 -- 136 samples
38 graded down on general appearance.
33 graded down on leaf and stem.
65 graded down on general appearance and leaf and stem.
U. S. No. 3 -- 17 samples
4 graded down on general appearance.
13 graded down on leaf and stem.
U. S. Sample Grade -- 2 samples
1 graded down on general appearance.
1 graded down on leaf and stem.
Washington, 173 Samples.
U. S. No. 1 -- 1 sample
U. S. No. 2 -- 74 samples
23 graded down on whole cones.
6 graded down on general appearance.
14 graded down on both whole cones and general appearance.
1 graded down on whole cones, general appearance, and stem
and leaf.
U. S. No. 3 -- 83 samples
74 graded down on whole cones.
4 graded down on general appearance.
1 graded down on leaf and stem.
3 graded down on whole cones and general appearance.
1 graded down on whole cones and leaf and stem.
U. S. Sample Grade -- 15 samples
13 graded down on whole cones.
2 graded down on general appearance.
10
By eliminating whole cones as a grading factor, the Washington hops
would grade as follows:
U. S. No. 1 -- 49 samples
U. S. No. 2 -- 117 samples
108 graded down on general appearance.
3 graded down on leaf and stem.
6 graded down on general appearance and leaf and stem.
U. S. No. 3 -- 5 samples
3 graded down on general appearance.
2 graded down on leaf and stem.
U. S. Sample Grade -- 2 samples
Both down on general appearance (specifically damage).
California, 150 Samples
U. S. No. 1 -- 10 samples
U, S. No. 2 -- 79 samples
15 graded down on whole cones.
18 graded down on general appearance.
1 graded down on leaf and stem.
38 graded down on whole cones and general appearance.
3 graded down on whole cones and leaf and stem.
2 graded down on whole cones, general appearance and leaf and
stem.
2 graded down on general appearance and leaf and stem.
U. S. No. 3 -- 57 samples
45 graded down on whole cones.
8 graded down on general appearance.
2 graded down on leaf and stem.
1 graded down on whole cones and leaf and stem.
11
U. S. Sample Grade -- 4 samples
3 graded down on whole cones.
1 graded down on general appearance.
By eliminating whole cones as a grading factor, the California samples
would grade as follows:
U. S. No. 1 -- 40 samples
U. S. No. 2 -- 99 samples
79 graded down on general appearance.
6 graded down on leaf and stem.
14 graded down on general appearance and leaf and stem.
U. S. No. 3 -- 10 samples
7 graded down on general appearance
3 graded down on leaf and stem.
U. S. Sample Grade -- 1 sample
Graded down on general appearance (specifically damage).
Idaho
42 Samples
U. S. No. 1 -- No samples
U. S. No, 2 -- 1 sample
Graded down on whole cones and general appearance.
U. S. No. 3 -- 14 samples
All graded down on whole cones.
U. S. Sample Grade -- 27 samples
All graded down on whole cones.
By eliminating percentage of whole cones as a factor, the Idaho hops
would grade as follows;
U. S. No, 1 -- 11 samples
U. S. No. 2 -- 31 samples
All graded down on general appearance (specifically on color and
condition of lupulin).
A recapitulation of the above data are shown in Table 1-A.
Table 1 -A
Grade Distribution of Samples Graded Under Tentative Standards
No.
State
Samples
Grade Distribution According
to 1946 Hop Standards
No. 1
No. 2
No. 3
Sample Grade
Grade Distribu y on According to 1946 Hop Standards but with Broken Cone Factor Eliminated
No. 1
No. 2
No. 3
Sample Grade
Oregon
176
1
7
69
99
21
136
17
2
Washington
173
1
74
83
15
49
117
5
2
California
150
10
79
57
4
40
99
lo
1
42
0
1
14
27
11
31
0
0
Idaho
13
PHYSICAL ANALYSIS OF THE 1949 CROP
IN RELATION TO TENTATIVE HOP STANDARDS
From the tabulation of grades and the factors responsible for placing
the sample in that grade, it can be readily seen that the percentage whole
cones is the limiting factor in most cases. Next most important factor is
the general appearance. In some of our previous studies on these standards,
leaf and stem content was most often the limiting factor. Since leaf and
stem content is very minor insofar as the grading of the hops is concerned
in this year, it tends to prove the theory that the over-all effect of a
standard is to improve quality. Since the adoption of the hop analytical
program to analyze for seed, stem and leaf, the stem and leaf percentage has
been continually dropping. There is no reason to suspect that the percentage
whole cones will not improve as well if this factor were incorporated into
the present analytical program. It is quite apparent from looking at these
grades that if whole cones were eliminated, then general appearance would be
the limiting factor in most cases. This general appearance, more than anything else, reflects the general handling and drying of the hops.
This
factor also has considerable room for improvement. These various factors
will b e broken down and taken up in more detail in the following portion of
this report.
For the purpose of research on the physical factors in the hop
standards, certain of the factors were rated differently than called for in
the standards. General appearance was divided into certain component parts:
(1) General appearance and total discoloration; (2) color and condition of
lupulin, and (3) damage were all rated separately and then combined into
general appearance for the numerical grade. These factors were also rated
on a numerical scale of 1, 2, 3, and 4, for the purpose of statistical
analysis in place of excellent, good, and fair as called for in the standards.
The amount of lupulin was estimated on the scale of from 0 to 9, in
keeping with previous research work, although the special grades require only
three classifications, namely, fat, normal, and thin.
In all cases the aroma was found to be acceptable, so this factor will
not appear in the analysis at any time.
The percent seed, stem and leaf was determined by the official
Federal-State Analytical Method,
Table 1 presents a summary of the special grades for seed content in
the 1949 grading studies. As was proposed in 1943, this uses the seedless
grade of 3 percent maximum, semi-seedless up to 6 percent maximum, and seeded
over 6 percent. This table shows that l /ashington is predominately a seedless
hop area, while Oregon is predominately a seeded hop area. California is
about equally divided between seeded and seedless hops, the seedless hops
being from the Sacramento area and the seeded hops being from the Santa Rosa
area. The Idaho hops are nearly all seedless.
It is interesting to note that
the semi-seedless classification is practically eliminated in the 1949 crop.
Only 7.8 percent of the entire number of samples under study fall in this semiseedless classification, Since the number of samples in this study was not
strictly proportional to the number of bales produced in the different states,
it is probable that there were quite a few more seedless hops grown in 1949
than there were seeded or semi-seedless.
114
Table 1
Summary Table of Special Grades For
Seed Content in the 1949 Ea Gm Studies
Number of Samples in Each Grade*
Number
of
Origin
Samples
Seedless
SemiSeedless
Seeded
Oregon
Washington
California
Idaho
176
173
150
130
11
17
77
9
142
26
64
142
35
5
2
All Samples
5141
265
142
234
Semi,
Seedless
Seeded
23
Percentage of Samples in Each Grade
Number
of
Origin
Samples
Oregon
Washington
California
Idaho
176
173
150
All Samples
Seedless
42
13.0
75.1
51.3
83,3
6.3
9.8
6.0
11.9
80.7
15.1
42.7
4.8
5141
48.9
7.8
43.3
Cumulative Percentage of Samples in Each Grade
Number'
of
Origin
Samples
Seedless
SemiSeedless
Seeded
Oregon
Washington
California
Idaho
176
173
150
42
13.1
75.1
51.3
83.3
19.3
84.9
57.3
95.2
100.0
100.0
100.0
100.0
All Samples
5141
148.9
56.7
100.0
* Limit for grade:
Seedless, 3%; semi-seedless, 6%; seeded, over 6%.
15
Table 2 shows the summary for the grading on the basis of leaf and stem
content in the 1949 hop crop. This table is set up on the basis of the recommended grade limits of 1946; that is, the limit in No. 1 as 5 percent, in No.
2 as 8 percent, in No. 3 as 11 percent stem and leaf. All the samples from
Idaho were under 5 percent in stem and leaf, while 93.6 percent were under 5
percent in Washington. California had 84.6 percent under that limit and Oregon
only 36.3,
Table 2
Summary Table for Grading on the Basis of Leaf and Stem Content
Number of Samples in Each Grade*
Number
of
Origin
Samples
Oregon
Washington
California
Idaho
176
173
150
42
All Samples
5141
2
3
4
64
162
127
42
98
9
20
13
1
2
0
0
1
2
3
3
Percentage of Samples in Each Grade
Number
of
Origin
Samples
Oregon
Washington
California
Idaho
All Samples
176
173
150
42
36.3
93.6
84.6
100.0
* Limits:
7.4
1.2
2.0
0,6
3
4
99.4
100.0
100.0
100.0
541
Cumulative Percentage of Samples in Each Grade
Number
of
Origin
Samples
1
Oregon
Washington
California
Idaho
All Samples
55.7
5.2
13.4
14
176
173
150
42
541
36.3
93.6
84.6
100.0
No. 1, 5%; No. 2, 8 %; No. 3, 11%.
2
92.0
98.8
98.0
16
Table 3 gives a summary of the ratings for total discoloration and
general appearance in the 1949 hop grading studies. Since general appearance
is more or less a complex factor, the color and condition of lupulin and
damage were rated separately. Therefore, this table does not include those
portions of general appearance.
The percentage of hops grading No. 1 was
97.6, 64.2, 55.4, 51.3 for Idaho, Oregon, Washington, and California re
spectively, with the over-all average of 60.4 percent of the samples grading
No. 1 on total discoloration and general appearance. As the inspectors were
going through the samples, it was apparent that a good deal of discoloration
resulted from improper handling. Much of this discoloration was attributed
to sack burn where the hops had been piled up for too long a period prior to
drying. In most cases this burn was not severe enough to cause actual damage
to the hops but it did materially affect the over-all appearance of the sample.
In a few cases it seemed that there might have been some dust or spray injury
which caused a slight diacoloration on the hops. There was only a moderate
amount of discoloration due to wind whip and damage of that sort, although
there were one or two samples that showed some evidence of possible hail
damage. The inspectors, however, did feel that in practically all cases the
discoloration could have been controlled to some extent by either more careful handling from the time of picking to drying or, in the case of discoloration due to red spider, the hops could have been more thoroughly dusted during
the growing season.
17
Table 3
Summary Table for Total Discoloration and General Appearance
Number of Samples in Each Rating on Total Discoloration and General
Appearance
Number
of
Samples
Origin
2
1
3
Oregon
Washington
California
Idaho
176
173
150
42
113
96
All Samples
541
41
58
73
67
1
5
4
5
0
0
0
1
0
327
199
14
1
77
Percentage of Samples in Each Rating on Total Discoloration and General
Aoearance
Origin
Number
of
Samples
Oregon
Washington
California
Idaho
176
173
150
42
64.2
55.4
51.3
97.6
All Samples
541
60.4
1
3
14
32.9
42.2
44.7
2.4
2.9
2.4
3.3
0.0
0.0
0.7
36.8
2.6
0.2
2
Cumulative Percentage of Samples in Each Rating on Total Discoloration
and General Appearance
Number
of
Origin
Sam les
2
1
3
Oregon
Washington
California
Idaho
176
173
150
42
64.2
55.4
51.3
97.6
97.1
97.6
96,0
100,0
100.0
100.0
99.3
100.0
All Samples
541
60.4
97.2
99.8
100.0
18
Table 4 gives a summary of the ratings on the amount of lupulin in
the 1949 hop grading studies. The samples of hops were rated for amount of
lupulin on a scale from 0 to 9 for the purpose of applying the special grades,
thin and fat. It has been the policy to consider anything under 5 as being
thin and anything over 7 as being fat. This summary bears out the opinion
that there were very few extremely thin hops or very few very fat hops in
the entire crop.
There were more thin hops in Oregon than in the other
states.
These were mostly of the Fuggles variety. In most cases these hops
were so badly shattered that a good deal of the lupulin had been lost and
the estimation of quantity of lupulin was very difficult.
The same thing
was true in estimation of some other qualities. The poor condition of many
of the samples led the inspector to believe that his estimates on quantity
of lupulin were not as accurate as they would have been on better samples.
However, in reviewing the 541 samples in the study, the inspectors reversed
themselves or changed grades but five times. This indicates that they were
quite consistent in spite of the condition of some samples. The inspectors
also had a feeling that possibly they were finding the range of estimates
within narrower limits than had been done in the past. In view of this it
was thought possibly that the six classifications should be the average or
normal hop and that anything below the six classifications (3,)4,5,6,7,8)
would be thin and anything over these six would be fat. On this basis then,
28.9 percent of the samples would be fat and 20 percent would be thin.
If
this crop is nearly normal or average this would seem to be a pretty good
segregation,
19
Table 4
Summary Table of Ratings on Amount of Lupulin
Number of Sam les in Each Ratin
Number
of
Origin
Samples
Class
Oregon
Washington
California
Idaho
176
173
150
42
1
1
All Samples
541
2
4
5
16
23
31
12
6'
7
48
39
48
4
6
6
5
4
82
88
78
34
31
70
282
139
17
Percentage of Samples in Each Rating Class
Number
of
Samples
Origin
3
4
5
6
7
8
9.1
4.7
4.6
13.1
17,9
8.0
9.5
46.6
50.8
52.0
80.9
27.2
22.6
32.0
9.6
3.5
3.5
3.4
5.7
13.0
52.1
25.7
3.2
Oregon
Washington
California
Idaho
176
173
150
42
0.5
0.5
All Samples
541
0.3
8
7
Cumulative Percentage of Samples in Each Rating Class
Number
of
Origin
Samples
Oregon
Washington
California
Idaho
All Samples
5
6
7
8
9.6
5.2
4.6
22.7
23.1
12.6
9.5
69.3
73.9
64.6
90.4
96.5
96.5
96.6
100.0
100.o
100.0
100.0
6.0
19.0
71.1
96.8
100.0
3
4
176
173
15o
42
0.5
0.5
541
0.3
20
Table 5 is a summary of the grading on color and condition of lupulin
in the 1949 hop grading studies. There were only five samples in the entire
study that rated below No. 2 on color and condition of lupulin.
Table 5
Summary Table for Rating on Color and Condition of Lupulin
Number of Samples in Each Rating on Color and Condition of Lupulin
Number
of
Origin
Samples
1
2
3
Oregon
Washington
California
Idaho
176
173
150
42
74
60
87
All Samples
5)a
232
100
110
63
2
0
3
0
0
0
31
0
0
3014
5
Percentage of Samples in Each Rating on Color and Condition of Lupulin
Number
of
Origin
2
Samples
1
3
Oregon
Washington
California
Idaho
176
173
150
42
42.0
34.6
58.0
26,1
56.8
63.6
42.0
73.9
1,2
1.8
0.0
0.0
0.0
0.0
0.0
0.0
All Samples
5141
42.8
56.2
1.0
0.0
Cumulative Percentage of Samples in Each Rating on Color and Condition of
Lupulin
Number
of
Origin
Samples
1
2
3
Oregon
Washington
California
42.0
34.6
58.0
26.1
98.8
98.2
100.0
100,0
100.0
100,0
Idaho
176
173
150
42
All Samples
541
42.8
99.0
100.0
The inspectors found this factor the most difficult of all the factors
to apply to the 1949 crop, particularly to the grades 1 and 2. The inspectors
had a definite feeling that there was more variation within samples than was
encountered in any previous year's study. It was seldom that any samples were
found where the lupulin was all No. 1 or all No. 2. Normally, there was a
23.
variation from 1 to 2 and in practically all samples it called for a decision as to how much of the No. 2 lupulin was present. Therefore, this
factor really had the two variables, one an estimate of quantity of each type
of lupulin, and one an estimate of the quality of the lupulin. The reason for
the high percentage (56.2 percent) in the No. 2 grade is probably due to the
fact that the Washington Early Cluster crop was harvested more or less immature, whereas the Oregon Fuggles crop seemed to be on the overmature side.
Most of the samples that showed these characteristics were not rated higher
than No. 2. The Idaho crop was 73.9 percent No. 2 but it was thought that
this was probably due to drying or possibly the condition at harvest.
Table 6 presents a summary for the grading on damage in the 1949 hop
As has been previously mentioned, there was not as much damage in 1949
as in orevious years viewed by the inspector. There was, however, a considerable amount of slight damage which was reflected more as total discoloration than as actual damage. Throughout the crop the usual traces of damage
due to mechanical causes, some maturity damage, some insect (primarily from
red spider), traces of mold and mildew were noted. The unusual thing about
the damage factor in the 1949 crop is that there was not a single sample in
Oregon graded down because of mildew damage. Mechanical damage, maturity,
and mold were the primary damages responsible for grading these samples lower
than No. 1. In any event, this was an excellent crop from the standpoint of
actual damage.
crop.
22
Table 6
Summary Table of Rating of Damage
Number of Samples in Each Rating on Damage
Number
of
Origin
Samples
1
Oregon
Washington
California
Idaho
176
173
150
42
162
159
117
All Samples
541
480
Percentage of Samples in Each Ratin
Number
2
3
4
13
9
27
0
1
3
2
5
1
49
8
4
3
4
7.4
5.2
0.0
1.7
18.0
3.3
0.6
1.2
0.7
9.0
1.5
0.8
3
4
99.4
97.1
96.0
99.4
98.8
99.3
100.0
100.0
100.0
97.7
99.2
100,0
42
on Damage
of
Origin
Samples
1
Oregon
Washington
California
Idaho
All Samples
176
173
150
42
541
92,0
91.9
78.0
100.0
88.7
Cumulative Percentage of Samples in Each Rating on Damage
Numberof
Ori in
Sam les
2
1
Oregon
Washington
California
Idaho
All Samples
.
176
173
150
42
.
541
92.0
91.9
78.0
100.0
88.7
23
Table 7 is a summary of the percentage whole cones in the 1949 hop
grading studies. This table is set up so that the hops are tabulated in 5
percent classes. As pointed out previously, Oregon and Idaho are definitely
low in the percentage of whole cones. Washington and California were somewhat better with California being the highest in percent of whole cones. On
the basis of the standards in which 70 percent whole cones is the minimum of
the No. I grade, 98.8 percent of the Oregon samples below, 94.7 percent of
the Washington samples below, 77.4 percent of the California samples, and
all of the Idaho samples would fall below this minimum.
For the crop as a whole, 91.6 percent would have less than 70 percent
whole cones. Due to the present methods of handling hops for determination
of percentage whole cones, additional work was done on this factor, but it
would be well to point out at this time the relationship of the percentage
whole cones below the 50 percent whole cones classification:
86.3, 5)4.6,
20.7, 95.2, and 52.3 percent of the total samples fell under 50 percent for
Oregon, Washington, California, Idaho, and the entire crop respectively.
The high percentage of samples in these lower classifications as to
whole cones is due to several factors. Through the surveys of the industry
it was pointed out that this crop was handled much more rapidly than in
practically any prPvious year. The hops were picked, dried, and baled during
a relatively short time. The normal process in the past has been to leave
the hops in a cooling or curing room for a month or two after drying. This
year the hops were practically all inspected within that period, indicating
that the hops were baled much earlier than normal. With the increase in
custom picking it has been a policy for several growerst crops to be run
through a single set of picking machines, kilns and balers. Therefore, it
is a common practice for the hops to be dried and baled immediately to make
room for the succeeding grower's crop. Baling so soon after drying does
not give the hops an opportunity to toughen up and become shatter-resistant
before they are baled. The weather conditions this season undoubtedly had
some effect on the broken condition of the hops as well. Additional information will be given in the later sections of the report showing the importance of this whole cone factor. But it would seem that anything the
growers could do to keep the hops from breaking would be highly desirable.
Consideration of the results obtained from applying the tentative
hop standards to the samples from the 1949 crop emphasizes the necessity for
a critical evaluation of all factors. From the application that has been
is
made to the current crop, it would appear that some adjustments are necessary
in the case of broken cones. It would appear also that possibly the semiseedless classification may not be necessary. The application of the factors
of General Appearance and Leaf and Stem provides a reasonably satisfactory
grade distribution. Information will be presented to show the range of the
several factors and the relationship existing between them. Significance
and deficiencies of the data presented will be pointed out in an attempt to
provide information which can be used in determi n i n g: (1) whether satisfactory grades are possible, and (2) how the various factors can be used
most effectively.
Table 7
Summary Table of Percentage "Whole Cones in the 1949 Hop Grading Studies
Number of Samples in each Class
0
Number
5
of
to
to
Origin
Samples
4
9
Oregon
Washington
California
Idaho
All Samples
176
173
150
42
541
4
10
15
to
20
to
25
to
14
19
24
29
34
39
8
12
29
12
3
33
10
176
173
150
42
541
30
to
2
1
4
1
8
4
12
Percentage of Samples in Each Class
0
Number
5
lo
of
to
to
to
Samples
Origin
4
9
14
Oregon
Washington
California
Idaho
All Samples
to
2.2
4.6
0.1
9.6
1.5
9.5
2.2
2.3 11.9
All Samples
541
0,1
2.2
1.6
60
65
to
to
to
44
49
54
59
64
69
70
to
74
20
11
4
18
12
8
16
24
17
3
3
12
31
17
1
41
60
61
5
22
20
1
48
40
45
5o
to
to
to
44
49
54
2
9
15
33
17
54
7
42
15
20
to
19
to
25
to
29
30
to
34
35
to
39
24
6.8 16,5
7.1
2.8
9.5
6.1
;1/7i.
176
173
15o
42
55
to
4
Cumulative Percentage of Samples in Each Class
Number
0
5
10
15
20
of
to
to
to
Origin
Samples
tc9)
Oregon
Washington
California
Idaho
50
to
to
3
.
2,3
45
35
40
to
55
to
59
30
35
to
to
40
45
50
55
6.8 13.6 30.1 36.9 55.6 67.4 77.2 86.3 93.1 96.0
1.7 7.5 13.8 20.8 34.6 52.6 65.3
1.3 4.0 9.4 20.7 32.0 45.4
21.4 28.5 38.0 42.8 64.2 80.9 88.0 95.2 97.6K0.0
3.8 6.6 12.7 15.8 25.8 33.6 41.2 52.3 63.5 72.4
to
79
84
3
2
2
24
16
7
2
22
11
1
62
42
31
13
1
6o
65
80
to
to
64
69
70
to
74
75
to
to
84
60
65
to
P4;
80
to
27
32
6.8 18.7 11.4 10.2 9.1 6.8 2,9 1.7 1.1 1.2
1.7 5.8 6.3 1.0 13.8 18,0 12.7 15.6 13.8 4.1
1.3 2.7 5.4 11.3 11.3 13.4 21.3 10.7 14.6
4.8 21.4 16.7 7.1 7.2 2.4 2.4
3.1 10.0 7.8 7.6 11.1 11.2 8.9 11.5 7.7 5.8
25
75
70
to
79
1.2
7.4
0.6
2.4
0.2
75
to
8o
to
1(34
97.7 98.8 100.0
80.9 94.7 98.8 100.0
66.7 77.4 92.0 99.4 100.0
83.9 91.6
97.4
99.8 100.0
25
EFFECT OF METHODS ON BLOKEN CONE DETERMINATIONS
In the original work to determine the percentage of whole cones, the
standard cut sample rather than the core sample was used and the whole cones
were picked from the sample by hand and the percentage determined in this
manner. Preliminary work on this same type of sample indicated that sieving
the hops over a 30/64 round hole sieve gave approximately the same result as the
percentage whole cones picked by hand, Since sieving was a mechanical determination which was much more rapid than hand picking, it was felt that
this could be substituted as a method of determination. In order to provide
more accurate information as to the effects of sampling or methods of analysis
on the percentage of broken cones, aciiitional tests were made. Samples were
cut from five different bales in three lots and a core sample was drawn adjacent to each cut sample. An analysis of variance was run on the amount of
broken cones as determined by the hand picking and by the sieving methods.
The analysis present in Table 8 shows there is a significant difference between hand picking and sieving and also a significant difference between cut
and core samples.
Table 8
Analysis of Variance of Relationship Between Hand Picked Whole Cones
Versus Sieved Whole Cones in Samples Taken la Cutting and with Core Sampler
Source of
Variation
Sum of
Squares
d.f.
Variance
f.Value
M.S.D.
0.1
f.05
f.01
.05
Hand pick
vs.
Sieving
1122.3
1
1122.3
16,3034
4.04
7.19
4.30
5.73
Core sampling
444.4
1
444.4
6.46*
4.04
7.19
4.30
5.73
Lot
131.1
2
65.5
2.92
3.19
5.08
Cut vs.
Picking x
Sampling
0.55
1
.55
58.03
2
29.01
Lot x Sampling
156.30
2
76.15
Lot x Sampling
x Picking
402.07
2
201.03
Error
3301.85
48
68.78
Total
5616,60
59
Picking x Lot
Average hand picked
Average sieved
77.8
69.1
Average cut sample
Average core sample
*3 Significant at the one nercent level.
It. Significant at the five percent level.
76.2
70.7
26
The difference between cut and core samples, however, is significant
at only the five percent level.* The means of the hand-picked and sieved
samples are 77.8 and 66.9 respectively, showing that 8.7 percent is lost in
The mean of the cut samples
the sieving operation for these particular hops.
is 76.2 compared to 70.7 from the core samples, showing that 5.5 percent is
lost due to the core sampling. Compared to the old method of hand picking,
cut sample determination of broken cones from a core sample by the sieving
method accounts for an additional error of 15.2 percent. In addition to
the losses resulting from sieving and from the core samples, it was thought
The
there might be some loss where the hops were run over the Bates divider.
present method of obtaining a working sample requires the hops to be passed
over the divider four times. To check the possible loss, hops of both the
An
cut and core samples were sieved and run over the divider four times.
analysis of variance of these data presented in Table 9 shows significant
differences as a result of both the type of sampling and as an effect of the
divider. Both are significant at the 1 percent level.* In this case the
difference in means between the cut and core samples is 6.8 percent and the
over-all loss in the divider is 9.5 percent.
Table 9
P
Analysis of Variance for Relationship Between Cut and Core Samples
Sieved and Run Over the Divider Four Times
Source of
Variation
Sum of
Squares
Lot
M.S.D.
d.f.
Variance
f. Value
f.05
f.01
.05r
.01
50.13
2
25.06
Sampling
1727.89
1
1727.89
16.48**
3.92
6.84
3.30
4.38
Division
1674.56
4
418.64
3.99 **
2.44
3.47
5.23
6.92
Division x Lot
96.61
8
12.07
Division x
Sampling
13.61
4
3.40
1.58
2
0.79
40.33
8
5.04
Lot x Sampling
Lot x Sampling x
Division
Error
12,568.28
120
Total
16,172.99
149
104.73
Mean in Percentage Whole Cones
Average Gut sample
Average Cone sample
Average SieVe only
67.1
60.3
69.1
Average
Average
Average
Average
**Significant at the one percent level.
Division
Division
Division
Division
1
2
3
4
65.6
63.1
61.3
59.6
* Significant at 5 percent level means the odds are greater than 19 to 1 that
the difference is real and not due to chance.. Significant at the 1 percent
level means the odds are greater than 99 to 1 that the odds are real and
not due to chance samplihg.
27
With these preceding figures in mind, an additional experiment was run
on the divider alone where the hops were passed over the divider four times.
These data are presented in Table 10. Ten samples were passed through the
divider and compared to samples sieved only,. The analysis shows that there
was a significant difference between sieved only and those divided four times
and again sieved. This difference was significant at the one percent level
and shows there is a loss of 4.8 percent due to division alone. With these
losses in mind, as presented in Tables 8, 9, and 10, it would seem then that
approximately 20 percent of the whole cones are lost in the determination as
it is now carried on as compared with the method used when the standards were
originated in 1943. In view of this loss due to sieving and dividing core
samples, it would seem desirable then to alter the standards from the 70 percent whole cones requirement for No. 1, established on the basis of hand
picking cut samples, to 50 percent whole cones required for No. 1 with the
sieving method of determination.
Table 10
Analysis of Variance for Experiment to Determine the Amount of Cones
broken in the DiVide7W---
Source of
Variance
Sum of
Squares
Treatment
112.82
Bales
M.S.D.
d.f.
Variance
f. Value
f.05
f.01
.05
.01
1
112.82
93.24**
4.38
8.18
1.11
1.60
503.08
9
55.89
46.19**
3.42
3.52
Error
10.95
9
1.21
Total
626.85
19
*
10 samples from 10 bales put through divider four times and compared to
samples sieved only.
*f Significant at the one percent level.
Average Sieve only
71.2
Average Divided four times
66.4
Since moisture might become important in an inspection procedure, it
was felt desirable to check the difference between the surface moisture content of hops in the bale and hops drawn from the inside of the bale. Previous
studies along this line indicate that hops tend to become equalized with the
moisture content of the storage room on the surface of the bales, whereas the
inside of the bale tends to hold its moisture for considerable periods of time.
This is confirmed by the analysis of variance shown in Table 11. The data,
however, are not too conclusive since the three lots were uniform in moisture
content, both within lots and between lots. The difference between inside and
outside was, however, significant at the 5 percent level with the outside of
the bale being lower. These data would not be considered as being too conclusive except that this same difference has been observed in previous studies.
The difference has not always been in the same direction, however. In previous
studies where hops were put into storage quite dry they tended to pick up surface moisture to equal the moisture content of the rooms whereas if they were
put in wet, they would tend to lose moisture conditions in the storage room.
The center of the bale would pick up or lose moisture rather slowly.
28
Table 11
A Study of the Variation in Moisture Content
Between the Inside and Outside of Certain Bales of Hops
Outside
Sample No.
Inside
% H2O
METle No.
% H2O
L-3-1
7.6
L-3-1
8.0
L-3-2
7.0
L-3-2
7.2
L-3-3
7,2
L-3-3
8.2
L-3-4
7.1
L-3-4
6.3
L-3-5
6.6
L-3-5
6.5
L-23-1
7.5
L-23-1
7.7
L-23-2
7.8
L-23-2
8.0
L-23-3
7.3
L-23-3
8.6
L-23-4.
6.8
L-23-4
7.6
L-23-5
6.9
L-23-5
7.3
L-45-1
6.9
L-45-1
6.9
L-45-2
7.4
L-45-2
8.0
L-45-3
7.3
L-45-3
7.5
L-45-4
7.3
L-45-4
7.3
L-45-5
6.8
L-45-5
7.8
x Outside
7.17
x Inside
7.53
Analysis of Variance Table for Inside and Outside of Bale Sampling
Source of Variation
Sum of S uares
d.f.' Variance f, Value f.05 f.01
Inside and outside
0.970
0,970
.:02*
. 1
.2
Lot
0.740
2
0.370
1.832
Within lot
2.752
8
0.344
1.703
Error
3.638
18
0,202
Total
8.100
29,
t. Test
2.65*
* Indicates significance at 5 perpent level.
29
In the present inspection procedure for seed, stem, and leaves, the
larger lots of hops are broken into two or more parts for the analytical
-work.
Therefore, in 70 different cases it was possible to get paired samples
from these lots. These 70 pairs actually represent 70 different lots of hops.
The summary of the differences between these pairs is presented in Table 12
covering each of the factors under study in 1949.
The standard error shows
that the determinations are all quite reliable. It is interesting to note
that the standard error of the differences on stem and leaf content is more
than the standard error for seed content. The standard errors on general ap
pearance, color and condition of lupulin, and percent damage are quite small,
but the scale of evaluation was only 4 classifications. Therefore, this
standard error is a little misleading. The standard error on the amount of
lupulin, while higher than the three previously mentioned, is probably a
little more accurate in that the amount of lupulin is estimated on a much
broader scale, that is, a scale of ten variations. The standard errors for
percent moisture, percent alpha resin, and percent beta resin are all quite
small. The standard error on the percent whole cones shows that the method
now used is quite consistent in determining the percentage whole cones and
there is very little difference between paired samples in most cases.
.
30
Table 12
Summary Table of the Differences Between 70 Pairs of
Samples in the 19149 1122 Grading Studies for Each of the Factors Under Study
Rating
%
on
Stem General
Pair %
and AppearNo. Seed Leaf ance
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
0.0
0.2
0.0
0.2
0.0
0.5
0.1
0.2
0.2
0.3
0.1
0.1
0.2
0.0
0.2
0.3
0.0
0.5
0.2
0.8
0.5
0.6
0.2
0.6
0.9
0.4
0.7
1.0
0.6'
0.4
1.0
6.0*
1.5
1.2
0.4
0.2
0.1
0.0
0.1
0.0
0.2
0.0
1,2
0.3
1,0
0.3
0.6
1.1
0,1
1.0
1.5
0.0
0.3
0.1
1.3
0.6
0.2
0.4
0.2
0.4
0.1
0.5
0.1
1.6
0.0
0.0
0.0
0.2
0.6
0.3
0.1
0.9
0.1
0.9
0.2
0.4
0.6
2.8
1,1
0.9
0.5
0.1
0.5
0.2
0
0
0
0
0
0
0
0
1
0
1
1
1
0
0
1
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
1
0
0
0
0
1
0
0
Rating
on
Amount
of
Rating
on Color
and Condition
Lupulin Lupulin
1
0
0
0
0
0
0
0
1
1
0
0
2
0
0
1
1
1
0
0
0
2
0
1
0
0
1
0
0
0
1
1
2
0
0
0
0
1
0
1
0
1
0
0
0
0
0
0
0
0
1
0
0
0
1
1
0
1
0
1
0
0
1
0
1
0
0
1
0
1
0
1
0
0
1
1
1
1
0
0
0
0
0
1
Rating
%
%
on
Whole
Damage Moisture Cones
0
0
0
0
0
0
0
0
9
0
0
0
0
0
0
0
0
0
1
2
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
1
0
0
o
0
0
0.3
1,1
2.2
0.6
0.0
0,1
0.2
0.9
0,1
0.9
1.7
0.3
0.1
0.6
0.2
0.1
0.7
0.2
0.4
0.7
0.1
0.9
0.1
0.3
0.3
0.1
0,0
0.7
0.0
0.2
0.4
0.3
2.0
0.2
0.3
0.1
0.5
0.5
0.5
0.1
0.1
0.0
0
2
3
0
3
1
3
5
2
2
3
4
5
4
3
1
9
4
3
12
4
2
0
4
2
0
4
4
8
6
2
13
3
4
5
9
3
1
5
3
5
4
%
i
%
P
0.08 0.02
0.96. 1.26
0.45 2.08
0.76 0.21
1.59 1.94
0.40 0.76
0.33 1.06
0.16 0.46
0.03 0.24
0,18 1.22
0.15 0.20
0.39 0.15
0.35 0.21
0.13 0.63
0.31 0.38
0.40 0.59
0.02 1.39
0.27 0.08
0.05 0.10
0.74 0.91
0.23 0.47
0.07 0.64
0.20 0.29
0.22 0.50
0.20 0.66
0.38 0.83
0.55 0.82
0,22 0.26
0.60 0.75
0.27 0.31
0.09 0.26
0.99 0.46
0.13 0.02
0.03 0,07
0.14 0.29
0.22 0.13
0.17 0.26
0.10 0.11
0.19 0.64
0.83 0.99
0.19 0.02
1.52 1.99
31
Table 12 (cont'd)
Rating
%
on
Stem General
Pair %
and Appear-
No.
Seed Leaf ance
43
44
45
46
47
48
49
50
51
1.2
0.2
0.4
0.5
0.2
0.4
0.6
0.3
0.4
0.3
0.2. 0.2
0.3 0.0
0.4 0.1
0.4 0.1
0.2 0.2
0.2 0.4
0.2 0.0
0.1 0.2
0.5 0.2
0.6 0.3
0.3 0.1
2.1 0.5
0.0 0.8
0,0 0.1
0.2 0.7
0.0 0.3
0.6 0.8
0.1 0.3
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
0.5
0.5
0.7
0.0
0.6
0.3
1.7
0.0
0.2
0.2
0
0
1
0
1
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Rating
on
Amount
of
Lupulin
0
Rating
on Color
and Condition
Lupulin
0
0
1
0
0.081
0.057
0.041
0.052
0.372 0.038 0.055
0.47
0.34
0.10
0.43
3.93
0
0
1
2
0
0
1
1
0
1
0
0
0
0
0
0
1
1
0
0
1
1
0
1
0
1
S.E. 0.037 0.057 0.044
7
0.46
0.47
0.15
p
0
1
3
1
0
0
0
70
3
0
0
0
1
1
1
0
1
0
69
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
%
0.1
0.3
0.4
0.6
0.7
0.7
0.7
0.2
0.7
0.2
0.2
0.6
0.0
0.2
0.2
0.6
0.5
0.3
0,1
0.1
0.8
0.4
0.3
1.3
0.1
0.2
0.0
0.7
0
0
0
1
0
0
0
68
Rating
%
%
on
Whole
Damage Moisture Cones
0
0
0
0
0
0
3
1
7
0
2
3
7
5
9
6
2
2
6
14
4
10
4
0
1
2
10
5
2
1
2
4
3
0
0.37
0.39
0.68
0.20
0.12
0.53
0.29
0.56
0.18
0.04
0.48
0.25
0.05
0.16
0.27
0.68
0.88
0.48
0.14
0.17
0.75
0.17
0,52
0.23
0.10
0.07
0.53
0.00
0.35
0.59
0.19
0.55
0.13
0.21
0.39
0.43
0.42
0.16
0.06
0.22
0.05
0.16
0.45
0.27
0.90
1.06
0.46
0.27
0.15
0.69
0.58
0.30
0.05
0,07
0.08
0.61
0.23
0.49
* The difference on seed content for pair 32 was obviously an error so this
figure was eliminated from the standard deviation and mean.
32
CHEMICAL ANALYSIS
Chemical work on the 1949 crop commercial hop samples was directed
toward three primary objections. The first was to furnish analytical data
for the correlation of various physical factors with chemical composition.
The second was to compare the A.O.O.C. official moisture method with other
more rapid procedures. The third was to recheck certain regression equations which have been used here for some years in a rapid colorimetric
method for estimating hop soft resins. This method was developed by the
Agricultural Chemistry division of the Oregon Agricultural Experiment
Station and has been published elsewhere (1).
Relation of Physical Factors to Chemical Composition
This portion of the chemical study will be covered in another part
of this report and, therefore, will not be further discussed in this section.
Moisture Content of Hops
It is recognized by the trade and previous investigations have
shown that moisture content is an important factor in the keeping quality
and evaluation of hops. It is more or less generally accepted that 12%
moisture is about the upper limit that hops may contain without danger
of molding or otherwise going out of condition. Moisture content and
suitable methods for determining it are, therefore, important considerations in any proposed hop grading procedure.
Suitability of a method for use in a grading procedure depends to
a great extent on how rapid it is so in our study of moisture methods we
have been primarily concerned with speed rather than extreme accuracy.
As far as moisture content is concerned, we think that any method which
will give results within 1% of the true moisture is amply accurate for
hop grades.
The official method for hop moisture was used as a standard of
comparison in the work discussed below. This method, set up by the Association of Official Agricultural Chemists, calls for drying a 2.5gram sample of ground hops in a 55-mm. diameter aluminum dish for one
hour at 103°-104° C. The loss in weight is taken as moisture.
The short time interval between approval of this program and the
harvest made it impossible to test many of the moisture devices on the
market, but we were able to obtain two types in time to try out on the
1949 crop samples. One of them, the Master Moisture Meter made by the
C. H. Baldwin Company, Lansing 2, Michigan, employs the relationship
between moisture content of the sample material and the relative humidity
equilibrium set up when the sample material is stirred in a closed chamber
containing wet- and dry-bulb thermometers, The difference in the thermometer readings is dependent on the moisture content of the test material.
A calibration curve for any material is made by plotting wet- and drybulb thermometer differences against moisture for samples of known moisture
content.
(1) Second Annual Report of Investigations to Develop Hop Grades. D. D.
Hill and D. E. Bullis. August 1942. p. 64-69. A New Approach to the
Estimation of Hop Soft Resins by D. E, Bullis and Gordon Alderton.
Wallerstein Laboratories Communications 8, No. 24, p. 118-127 (August 1945).
33
About 200 samples were run on this instrument but the results
were very erratic.
It was quite evident that the machine as presently
developed is not at all suitable for determining moisture content of
hops. No purpose would be served by including a table of these data so
they are omitted.
The second instrument tried out was the Dietert Moisture Teller,
manufactured by the Harry W. Dietert Company, 9330 Roselawn Avenue,
Detroit 4, Michigan. This instrument blows a blast of heated air through
the sample which is held in a container with a very fine mesh screen
bottom. The drying temperature is thermostatically controlled to about
6° F. of the desired setting which gives a range of 10°,-15° F. Heat
and blower are both shut off at the end of any predetermined period by a
timing device.
An earlier model of this device had been used for hop moisture in
experimental work during 1943-1944. This work was reported in the Fourth
Report of Investigations to Develop Hop Grades by D. D. Hill, D. E. Bullis,
and J. D. Sather, November 1946.
Preliminary tests with the new improved machine indicated that a
temperature of about 200° F. for 8 minutes gave satisfactory results.
When dried at higher temperatures weight loss continued for longer periods
of time which appeared to indicate some decomposition in addition to the
moisture loss. Comparisons were made between the Dietert Tester and the
official method on all commercial samples used in this investigation.
In
general, there is good agreement between the methods for hops of low to
average moisture content. For high moisture samples it gives higher values
than the official method. However, our observations have led us to believe
that the error in these instances is in the official method rather than
in the Dietert test. We have noted that high moisture hops (10% moisture
or higher) continue to lose considerable weight when dried up to 3 or 4
hours under conditions specified by the official procedure.
The following table gives the maximum, average and minimum moisture
content encountered in the 520 commercial lots tested.
It should be noted
here that the high values were, in most cases, due to moisture absorption
in our storage room. We were unable on short notice to obtain sufficient
pliofilm bags to hold all the samples, The substitute bags were found
to allow some moisture absorption, the amount depending on the length of
storage time.
Moisture Content of 1949 Commercial Hop Samples
Official Method
Max.
Av.
Min;
Dietert Tester
Max.
Av.
California (150)*
11.8
8.34
6.4
12.3
8.10
Idaho (42)
10.9
5.0
7.62
10,0
7.18
8.60
Oregon (164)
12.6
6.9
12.6
8.51
Washington (164)
11.5
7.96
7.51
4.5
6.2
* Numbers in parentheses indicate number of samples tested.
Min.
6.5
5.1
5.6
5.5
34
For those who may be interested in the statistical treatment of
the data obtained by the two moisture methods, the following summary is
included. The correlation coefficient between the methods is .7761 and
the F-test shows significance at the 1% level. This means that the odds
are less than one in 100 that such a relationship would occur by chance.
The standard error of estimate is .7558.
In other words, the difference
in moisture content between the two methods will not differ by more than
: .7558% in 2/3 of the samples tested. The other 1/3 of the samples will
vary by more than that amount. The regression equation for expressing
the relationship is
Yx
im
2.5786
+
0.7108x
where Y is the percent moisture by the official method and X is the percent moisture by the Dietert test.
Soft Resin Contents of 1949 Crop Commercial Hops
From the standpoint of resin content, the 1949 hop crop in all
four states covered by this work was of better-than-average quality.
This may have resulted from a favorable season. However, it may be that
under the existing marketing agreement only the better quality hops were
harvested and thus the poor hops did not enter into the quality picture.
Analysis for soft resin content was made by the colorimetric
procedure previously mentioned. The following table gives the maximum
average and minimum values for alpha and beta resins by states. Early
and Late Clusters are classed together since they are very much alike
in resin content.
Soft Resin Content of 1949 Crop Hops
A Resin
State
California
Idaho
Oregon
Washington
Variety
Clusters
Clusters
Fuggles
Clusters
Clusters
(150)
( 42)
( 53)
(111)
(164)
Max.
Av.
9.43
7.80
7.12
8.75
8.03
6.53
6.14
4.88
6.39
6.10
B Resin
3.62
4.43
2.76
3.55
3.51
Max.
AV.
Min.
13.05
10.99
11.13
13.67
11.70
10.37
9.50
9.23
10.69
6.23
7.57
6.07
7.31
6.18
9.52
Comparison of Colorimetric and Gravimetric Methods for Hop Soft Resins
were
1940
from
some
beta
The data on which our colorimetric method (loc. cit.) was based
obtained originally from a limited number of commercial samples of
crop Oregon hops. In 1942, study of a larger number of 1941 lots
California, Oregon and Washington and a few from New York led to
slight revisions in the equations used to calculate the alpha and
resin percentages.
Since its development, we have used the method rather extensively
in our own laboratory when the accuracy of the official gravimetric
35
method was not necessary. It is rapid and thus would meet the main requirement demanded for inclusion in any grading procedure.
It was felt, however, that before the method could be recommended
for nation-wide grade usage it should be rechecked to determine if the
equations were still valid or if there were unknown factors such as
seasonal crop variation which might change the equations from year to
year and thus impair the general utility of the method.
To carry out this study, 186 lots were taken from the 520 used in
the 1949 crop program. There were 52 from California, 53 from Oregon,
52 from Washington, and 29 from Idaho. They were selected so that they
would represent a cross-section of the whole harvesting season in each
state.
The alpha and beta resin content of these samples was determined
by the official gravimetric method. The color value and petroleum-ether
solubles were determined as outlined in the colorimetric method. These
data were then subjected to statistical analysis from which multiple correlation coefficients, standard errors of estimate and multiple regression
equations were calculated. These values were then compared to those
obtained in the 1942 study.
The following tables list the pertinent data derived from the
1941 and 1949 investigations.
Number of Samples
1941 Crop
California
Oregon
Washington
Idaho
New York
Total
1249 Crop
52
53
52
33
44
44
-11
122
Multiple Correlation
Coefficient, R.
29
-1136
Standard Error
of Estimate, S.
1941 crop
199
4 crop
.8816
.9133
.5822
1941 crop
.8197
.8876
B Resin 1949 crop
.8204
.9418
A Resin
.5904
It will be noted that the multiple correlation coefficients and
the standard errors of estimate are in very close agreement in the two
studies.
36
The multiple regression equations derived from the 1941 crop data
are:
A
=
.1043S
+
.0280T
+
B
=
.6205S
-
.0052T
+ 1.3193
.3376
For the 1949 crop they are:
A
-
-.0860S
B
=
.69935
+
-
.0385T
.0182T
+
+
.9502
2.1182
In the above equations A is alpha resin, B is beta resin, S is
percent solids in petroleum-ether extract, and T is the color reading
on the Klett-Summerson Photoelectric Colorimeter.
At first glance it would seem that the equations are not at all
in agreement. However, when S and T values for a series of hop samples
were substituted in the two sets of equations, it was found that the calculated A and B percentages agree as well as might be expected for this
type of method.
The following table gives a comparison of alpha and beta resin
percentages obtained by the official method and by each set of multiple
regression equations.
.1.011/1111.111.1.1,1n
Sample
No.
2
11
25
28
42
53
6o
80
91
106
109
139-B
150
Official Method
A
B
6.92
7.90
8.53
5.38
6.85
8.7o
9.18
6.92
6,47
8.34
4.21
4.28
10.60
8.78
9.10
10.50
7.71
9.41
9.6o
10.42
10.90
11.59
11.34
7,09
9.64
11.85
Calculated from
1941 Equations
A
B
Calculated from
1949 Equations
A
6.58
7.90
6.88
7.69
4.09
7.03
8.64
8.90
7.28
6.47
8.26
4.25
4.94
9.80
10.02
9.49
11.62
7.03
10.77
11.30
11,76
10.89
10.55
11.94
7.50
8.99
13.36
8.64
8.02
4.69
7,2o
9.12
9.29
7.48
6.55
8.4o
4.74
5.10
9.90
9.59
8.39
10.95
7.07
10.30
10.24
10.69
10.34
10.27
11.18
7.56
9.06
12.22
37
Sample
No.
202
206
211
265
268
271
290
313
334
336
339
Official Method
a
A
4.85
4.59
4.19
4.92
10.50
5.63
6,50
6.77
7.26
5.71
6.35
6.7o
6.51
9.41
11.93
11.95
10.43
9.58
10.63
11.16
8.35
Calculated from
1941 Equations
A
4.44
4.12
3.68
5.18
9.42
6.78
6.39
6.95
6.98
6.12
4.75
4.71
7.04
7.76
7.41
6.83
9.09
13.52
11.40
10.24
10.16
10.86
10.75
6.56
7.65
11.53
4.89
4.60
4.23
5.39
9.35
6.66
6.55
7.32
7.10
6.03
5.01
5.29
6.94
7.80
7.52
7.01
9.07
12.57
11.16
9.94
9.61
10.43
10.66
8,63
7.55
11.21
4.56
4.92
8.19
8.00
6.41
8.33
4.22
8.10
7.00
5.89
7.27
10.18
10.25
10.52
7.66
10.29
9.26
lo.04
5.53
5.50
6.34
7.62
8.61
7.59
7.87
9.59
9.83
10.33
358-B
368
5,35
4.61
6.86
417
425
430
518
530
533-B
549
551
554
5.39
4.78
8.26
7.72
8,95
3.72
8.12
6.33
5.48
7.51
7.92
10.04
10.01
11.05
6.52
9.77
9.97
9.86
3.8o
4.33
7.84
7.69
8.04
3.84
7.79
6.59
5.85
6.38
7.28
10.96
10.97
11.32
7.43
11.03
9.74
10.13
704
4.86
4.65
6.26
7.47
8.79
7.17
7.86
9.82
4.93
4.97
6.12
7.26
8.23
7.77
8.01
9.86
10.46
11.22
717-B
723
732
734
8.37
9.40
10.51
9.86
Calculated from
1949 Equations
A
Alpha resin values calculated by the 1949 equation check more
closely with official method results than those obtained by use of the
older equation. That is to be expected inasmuch as the equations are
derived from these official method data. For beta resin, either set of
equations yield values about equally close to those obtained by the
official procedure.
If a choice were required we would favor the set of equations
developed from the 1949 data since the study includes a larger number
of samples than the previous study. Also the analyses were completed
in a much shorter time, which should have minimized such factors as
sample deterioration in storage.
However, if it is possible to do so, we recommend a repetition
of this phase of the investigation on the 1950 crop so that the equations may be made as accurate as such a method will permit.
38
THE RELATIONSHIP OF PHYSICAL AND CHEMICAL FACTORS IN HOPS
This section of the report will be presented separately from the
previous sections because of the technical aspect of the material. While
the same factors are used in this section, they are subjected to a detailed, statistical analysis and, thereforelthe results would be of a
more fundamental nature.than the results of grading as presented in the
previous sections. The separate factors which go to make up the grades
will be taken up individually.
In order to determine whether the differences in the leaf and
stem content in the different states were real or due merely to possible
error in sampling, an analysis of variance was run on the Late Cluster
machine-picked hops from the four states and is presented in Table 13.
The differences were found to be significant at the 1% level.
Idaho
had the more cleanly picked hops with 2.84%, California was next with
4.43, followed by Washington with 4.49 and Oregon with 5.96% stem and
leaf.
Table 13
Analysis of Variance, Leaf and Stem Classified by State
Late Cluster, machine-picked hops from California) Idaho, Oregon, and
Washington were used.
Means of Samples
California
Idaho
4.43 .c150)
2.84 (42)
Number of obaervationS is in parentheses
Variation
Due to
Sum of Squares
Degrees
of
Freedom
Oregon
Washington
5.96 (42)
4.49 (51)
Mean
Square
F
Remarks
Significant
20.82
ata% level
State
205.1964
3
68.3988
Error
923.1560
281
3.2853
Total
1,128.3524
284
An analysis of variance calculated on the amount of lupulin by
states is presented in Table 14. Late Cluster, machine-picked hops
from California, Oregon, Washington, and Idaho were used.
The difference
between the estimated amount of lupulin was found to be significant at
the 1% level. Oregon and California were found to have the same estimated amount of lupulin on the average with 6.2%.
Idaho was a little
lower with 6.0% and Washington was the lowest with 5,7%.
39
Table 14
Analysis of Variance, Amount of Lupulin Classified by State
Late Cluster, machine-picked hops from California, Oregon, Idaho, and
Washington were used.
Table of Means
California
Orepn
Idaho
Washington
6.2 (L2)
6.0 (L2)
6.2 (150)
Number of observations is in parentheses.
Variation
Due to
Sum of Squares
Degrees
of
Freedom
5.7 (51)
Mean
Square,
F
6.65
State
12.0970
3
4.0323
Error
170 . 3451
281
0.6062
Total
182.4421
284
Remarks
Significant
at 1% level
The amount of lupulin was also classified by variety and is presented in the analysis of variance in Table 15. The difference in the
amount of lupulin as to variety was found to be significant in machinepicked hops in Oregon where the varieties, FlIggles, Early Cluster, and
Late Cluster were used. The Early Cluster was found to have 6.8 estimated amount of lupulin, the Late Cluster 6.2, and the Fuggles 4.5.
The
Fuggles hop has shown same relative difference here that has been found
in past studies. The Early Cluster has not always been higher in past
studies.
Table 15
Analysis of Variance, Amount of Lupulin Classified by Variety
Machine-picked Oregon hops were used.
Cluster and Late Cluster.
The varieties were Fuggles, Early
Table of Means
Fuggles
Early Cluster
6.8 (8)
4.5 (16)
Number' of observations is in parentheses.
Late Cluster
6.2 (42)
Table 15 (Continued)
Variation
Due to
Sum of Squares
Degrees
of
Freedom
Mean
Square
F
42.45
Variety
41.2013
2
20.60065
Error
30.5714
63
0.48526
Total
71.7727
65
Remarks
Significant
at 1% level
An analysis of variance on color and condition of lupulin classified by state is presented in Table 16. Late Cluster, machine-picked
hops from all four states were used. The difference here was significant
only at the 5% level. Here, Washington and California were found to be
superior as indicated by the lower average grade for color and condition
of lupulin at 1.6.
Idaho was next with 1.7 and Oregon had 1.8. These
averages represent the average on that condition on the basis of grades
1, 2, 3, and 4.
Table 16
Analysis of Variance Color and Condition of Lupulin Classified by State
Late Cluster, machine-picked hops from California, Idaho, Oregon, and
Washington were used.
Table of Means
California
Idaho
Washington
Oregon
1.6 (51)
1.6 (150)
1.7 (42)
1.8 (42)
Number of observations is in parentheses.
Variation
Due to
Sum of Squares
Degrees
of
Freedom
Mean
Square
F
3.71
State
2.5578
3
0.8526
Error
64.6492
281
0.2301
Total
67.2070
284
Remarks
Significant
at 5% level
The color and condition of lupulin were also classified by variety
and the analysis of variance is presented in Table 17. The differences
were found to be significant at the 1% level. The Late Cluster variety
41
was found to have the poorest estimated color and condition; Early Cluster
next, with the Fugglas the best. These estimates, again, are the average
grade on the basis of 1, 2, 3, and 4.
Table 17
Analysis of Variance, Cold and Condition of Lupulin Classified by Variety
Machine-picked, Oregon hops were used.
Cluster and Late Cluster.
The varieties were Raggles, Early
Table of Means
Late Cluster
Early Cluster
fuggles
1.2 416)
1.4 (8)
Number of Observations is in parantheses.
Variation
Due to
Sum of Squares
Degrees
of
Freedom
1.8 (42)
Mean
Spare
F
13.96
Variety
5.3845
2
2.6923
Error
12.1458
63
0.1928
Total
17.5303
65
Remarks
Significant
at 1% level
The analysis of variance for the percent moisture, classified by
states, is presented in Table 18. Late Cluster, machine-picked hops from
the four states were used. The difference between the percent moisture
The
in the different states was found to be significant at the 1% level.
moisture contents were found to be on the average:
California, 8.34;
Idaho, 7.62; Oregon, 8.67; Washington, 8.47. It would be well to mention
at this time that the moisture content on these samples is not too accurate because of the way the samples were handled. At the time the
samples were drawn from the field, they were not placed in moisture-proof
containers, so in many cases the samples had quite a chance to change in
moisture content before they were analyzed for percent moisture.
Table 18
Analysis of Variance, Percent Moisture Classified by State
Late Cluster, machine-picked hops from California, Idaho, Oregon and
Washington were used.
Table of Means
California
Idaho
Oregon
8.67 (42)
7.62 (42)
8.34 (150)
Number of observations is in'parentheaes.
Washington
8.47 (51)
42
Table 18 (Continued)
Variation
Due to
Sum of Squares
Degrees
of
Freedom
Mean
S uare
State
27.1481
3
9.0494
Error
353.9850
281
1.2597
Total
381.1331
284
F
7.18
Remarks
Signi leant
at 1% level
The percent moisture was also classified by variety and analysis
of variance is presented in Table 19. The differences were found to be
nonsignificant. Therefore, it would seem that the weather conditions or
other factors at the time of sampling did enter into these figures as
suggested in the last paragraph concerning the percentage moisture classified by state.
Table 19
Analysis of Variance Percent Moisture Classified by Variety
Machine-picked, Oregon hops were used.
Cluster and Late Cluster.
Varieties were Fuggles, Early
Table of Means
Late Cluster
Early Cluster
Fuggles
8.67 (42)
8.54 (16)
8.19 (8)
Number of observations is in parentheses.
Degrees
Variation
Due to
of
Sum of Squares
Freedom
Mean
Square
Variety
1.6307
2
0.8154
Error
61.4275
63
0.9750
Total
63.0582
65
F
0.84
Remarks
Not
significant
Tables 20 and 21 show simple correlation coefficients for certain
of the factors in this study. Significant relationships were established
between the percentage whole cones and the moisture, between the percentage
whole cones and alpha resins, between the percentage whole cones and beta
resins. In all three cases, the relationship was found to be positive
and highly significant, showing that when the percentage of whole cones
increased, the percentage of moisture increased, and when the percentage
of whole cones increased, the percentage of alpha and beta resins both
increased. This is particularly important on the alpha and beta resins
because it does jusitfy the use of whole cones as a grading factor. Correlations were also run on the relationship between the percentage of
whole cones and color and condition of lupulin, the percentage whole cones
and the amount of lupulin, and the relationship between amount of lupulin
and the color and condition of lupulin. The percentage of whole cones
seems to have no relationship to the color and condition of lupulin.
However, the percentage of whole cones and the estimated amount of
lupulin did have a positive relationship showing that as the percentage
of whole cones increased, the estimated amount of lupulin increased.
This relationship was found to be highly significant.
There was no relationship between the color and condition of lupulin and the estimated
amount of lupulin.
Table 20
Simple Correlation Coefficients Between
Whole Cones, Koisture and Soft Resins
Table of r
nalysis used
Corrected by
Classification
Ignoring
Classification
0.2648
0.1261
.Resin A and % whole cones
0.2285
0.3591
Resin B and % whole cones
0.0910
0.1437
Variables
% whole cones and H2O oven
Table of F
Analysis
used
Variables
Corrected by
Classification
1 and 510
Ignoring
Classification
1 and 518
% whole cones and H2O oven
38.48**
8.37**
Resin A and % whole cones
28.10**
76.69**
Resin B and % whole cones
4.26*
10.92**
* Significant at the5% level.
** Significant at the 1% level.
The above table shows the values of simple correlation coefficients
calculated for three sets of variables and the F values which were used
to test their significance.
r2
F
1
with 1 and 518 degrees of freedom
r2
518
for data ignoring classification and
r2
F
with 1 and 510 degrees of freedom
r2
1
510
for data corrected by classification.
Table 21
Simple Correlation Coefficients Between Certain Physical Factors
Table of r
Corrected by
Classification
Ignoring
Classification
Color and Condition and % Whole Cone
0.0044
0.0605
Lipulin and % Whole Cone
0.1271
0.2441
Color and Condition and Lupulin
0.0078
-0.0033
Analysis Used
Variables
Table of F
Corrected by
Classification
Analysis Used
--------,
Degrees of Freedom
Variables
1 and 510
Color and Condition and % Whole Cone
0.01
Lupulin and ,4, Whole Cone
8.38**
Color and Condition and Lupulin
**Significant at the.1% level.
0.03
Ignoring
Classification
1 and 518
1.90
32.82**
0.01
The above table shows the values of simple correlation coefficients
calculated for the three pairs of variables and the F values which were
used to test their significance.
r2
F
1
with 1 and 518 degrees of freedom
r2
518
for data ignoring classification and
45
F
r2
with 1 and 510 degrees of freedom
1 - r2
510
for data corrected by classification.
An analysis of variance was calculated for the percent whole cones
classified by state. Late Cluster, machine-picked hops from the four
states were used and these data are presented in Table 22. The differences
in the four states were found to be significant at the 1% level. California
was found to have the highest percentage whole cones with 59.4, followed
by Washington with 50.1, Oregon with 34.5 and Idaho with 28.3. These
were calculated only on the Late Cluster hops because there were too few
number samples in the other classifications to be used in this study.
Table 22
Analysis of Variance, Percent Whole Cones Classified bey State
Late Cluster, machine-picked hops from California, Idaho, Oregon and
Washington were used.
Table of Means
California
Washington
Oregon
Idaho
28.3 (42)
59.4 (150)
Number of observations in parentheses.
Degrees
of
Freedom
50.1 (51)
34.5 (42)
Variation
Due to
Sum of Squares
State
43,041.9414
3
14,347.3138
Error
34,246.9920
281
121.8754
Total
77,288.9334
284
Mean Square
F
117.72
Remarks
Significant
at 1% level
The percentage of whole cones was also classified by variety and
the analysis of variance is presented in Table 23. Machine-picked hops
from Oregon were used and the varieties wereaggles, Early Cluster, and
Late Cluster. The differences were found to be significant at the 1%
level. The Early Cluster variety was found to have the highest percentage
whole cones with 44.4, followed by Late Cluster with 34.5%, and Fuggles
with 20.1%.
46
Table 23
Analysis of Variance, Percent Whole Cones Classified ly Variety
Machine-picked, Oregon hops were used.
Cluster and Late Cluster.
The varieties were Fuggles, Early
Table of Means
Fuggles
Late Cluster
Early Cluster
20.1 (16)
44.1 (8)
Number of observations is in parentheses.
Variations
Due to
Sum of Squares
Degrees
of
Freedom
34.5 (42)
Mean Square
Variety
3p721.5295
2
1,860.7647
Error
6,366.2887
63
101.0522
Total
10,087.8182
65
F
18.41
Remarks
Significant
at 1% level
The whole and broken portions of samples of hops were analyzed to
determine just what difference there was in the two constituents. The
analysis of variance for these differences between the whole and broken
portions for all classifications is presented in Table 24. The differences
in the whole and broken portions were found to be significant at the 1%
level. The mean alpha resin for all classifications is presented in
Table 24A.
Table 24
Analysis of Variance, Alpha Resin Difference Between
Whole'andbroken Cones-T.3F TIYNine Classifications
Table of Means of Differences
',Picking
Staie'--,
Fuggles
Machine
Hand
Early Cluster
Machine
Hand
Late Cluster
Hand
Machine
California
2.2705 (148)
Idaho
1.8679 ( 42)
Oregon
1.0362 (16) 0.5368 (37) 1.8225
(
8)
Washington
1.9579 (113)
Number of observations in parantheses.
1.8062 ( 42) 1.7216 (61)
2.0925 ( 51)
147
Table 214 (Continued)
Degrees
of
Variation
Due to
Sum of Squares
Mean
Freedom Square
Classification
105.5892
8
13.1986
Error
289.5804
509
0.5689
Total
395.1696
517
F
23.20
Remarks
Significant
at 1% level
Table 24A
Table of Means, Alpha Resin Content
Whole Cone Portion
--- .kicking
State--,
Fuggles
Machine
Hand
Early Cluster
Machine
Hand
Late Cluster
Machine
Hand
California
7.141461
Idaho
7.4014 ( 42)
Oregon
14.71400 (16) 5.6705 (37) 6.9225
(
8)
Washin ton
6.8123 (113)
umber or o serva ions in parentheses.
.._
7.1883
(148)
( 142)
7.6826 (61)
7.3657 ( 51)
Broken Cone Portion
---,E#king
State'
Fuggles
Machine
Hand
Early Cluster
Machine
"Hand
Late Cluster
Machine
Hand
California
5.1757 (148)
Idaho
5.5336 ( 42)
Oregon
3.7038 (16) 5.1338 (37) 5.1000
(
8)
Washington
4.8544 (113)
umber or o serve ions in parentheses.
5.3821 ( 42) 5.9610 (61)
5.2688 ( 51)
The mean alpha resin presented in Table 24A shows that in every
classification the whole cone portion is superior to the broken portion
in alpha resin content. The mean differences presented in Table 25 show
that there does not seem to be much variation between the four states for
differences between whole and broken portions of machine-picked
Late Cluster hops. The greatest difference was in California and
Washington hops.
Oregon also had a little less difference than did
148
Washington for Early Cluster hops. These small variations between the
states should be questioned, however. Since Washington and California had
a much higher percentage of whole cones, the results are not quite comparable.
Table 25
Analysis of Variance of the Difference in Alpha Resin Content Between Whole
and Broken Con-grin Oregon Machine and Hand-77MHops
Ruggles and Late Cluster varieties were used in this analysis.
Alpha Resin
Table of Means of Differences
-Method of Picking
State
Fules
Machine
Late Cluster__
Hand
Machine
Hand
Oregon
1.0362 (16) 0.5368 (37) 1.8062 (42)
Number of obserVations in parentheses.
Variation
Due to
Sum of Squares
Classification
42.9217
Error
54.0270
Degrees
of
Freedom
1.7216
(61)
Mean
Square
F
Remarks
3
14.3072
40.26
**
152
0.3554
Picking
1
1.6375
4.61
*
Variety
1
37,8751
106.57
**
Interaction
Significant at the 1% level.
* Significant at the 5% level.
1
1.3263
3.73
4$4('
The analysis of variance for the differences between whole and
broken cones in Oregon on machine and hand-picked hops shows significance
at the 5% level for picking and 1% level for variety. The difference
for machine-picked Fuggles is almost twice the hand-picked difference.
This indicates that the Fuggles hops tend to shatter and lose more resin
in maching picking. There does not seem to be as great a difference between the machine and hand-picked Late Cluster. However, the differences
between whole and broken portions are greater on Late Cluster hops than
they are on Fuggles.
The same analyses and.tables for beta resin are presented in Tables
26, 26A and 27. These analyses show the same differences between whole
and broken cone portions for beta resin that was shown for alpha.
The
interaction variety X picking is significant at the 5% level for beta resin
49
but not for alpha. This indicates that varieties may respond differently
in respect to losses of beta resin when hand or machine picked. The mean
differences for Fuggles show 0.9969 difference on machine picked and
0.3032 for hand picked, whereas the Late Clusters show 1.87 for machine
picked and 1.86 for hand picked.
Table 26
Analysis of Variance of Beta Resin Differences Between Whole
and Broken Cone TOAITRine Classifications
___
Table of Means of Differences
Flies
---Q:cking
State --.
Machine
Hand
Early Cluster
Lachine
Hand
Late Cluster
Machine
Hand
California
2.3928 (148)
Idaho
2.0998 ( 42)
Oregon
0.9969 (16) 0.3032 (37) 1.9900
8)
(
Washington
2.0294 (113)
umber oz o serva lops in parentheses.
Variation
Due to
Sum of Squares
Classification
159.8881
Error
Total
Degrees
of
Freedom
1.8700 ( 42) 1.8610 (61)
2.4859 ( 51)
Mean
Square
F
8
19.9860
22.22
457.8688
509
0.8995
617.7569
517
Remarks
Significant
at 1% level
Table 26A
Table of Means, laeuiResin Content
Whole Cone Portion
*,picking-
State --.
Fug4les
Machine
Hand
Early Cluster
Machine
Hand
'Late Cluster
Machine
Hand
California
11.3587
Idaho
11.0126 ( 42)
Oregon
7.8256 (16) 9.6035 (37) 10.7175
(
8)
Washington
10.1051 (113)
Number of observations in parentheses.
(148)
11.5238 ( 42) 12.1900 (61)
11.3337
( 51)
50
Table 26A (Continued)
Broken Cone Portion
----picking
State-----...,
Fuggles
Machine
Hand
Early Cluster
Machine
Hand
Late Cluster
Machine
Hand
California
8.9759 (148)
Idaho
8.9129 ( 42)
Oregon
7.8256 (16) 9.6035 (37) 8.7275
(
8)
9.6538 ( 42) 10.3290 (61)
Washington
8.0758 (113)
Number of observations 'in parentheses.
8.8478 ( 51)
Table 27
Analysis of Variance of Differences Between Whole
and Broken Cones for Four Classifications
Beta Resin
Table of Means of Differences
'--- --..fie hod of Picking
State
Oregon
um-r o
Fuggles
Madhine
Hand
Late Cl us ter
Machine
Hand
0.9969 (16) 0.3032 (37) 1.8700 (42) 1.8610 (61)
o servations in paren eses.
Variation
Due to
Classification
Sum of Squares
Degrees
of
Freedom
Mean
Square
F
69.3429
3
23.1143
113.3100
152
0.7455
Picking
1
1.7597
2.36
Variety
1
61,1014
81.96
Interaction
Significant at the 1% level.
* Significant at the 5% level.
1
3.6173
4.85
Error
31.01
Remarks
**
**
51
The analysis of variance and table of means for total soft resin
are presented in Tables 28 and 28A. Since total soft resin is merely a
combination of alpha and beta resin, this table of means and mean differences gives a more complete picture of what is lost in broken cones.
Note that the range in loss of resin in the broken cones on Late Clusters
is 3.5826 on Oregon hand picked to 4.6632 for California machine picked,
or an average loss of 4.09 total soft resins.
If a hop had only 50%
whole cones, then this would mean that about 2% of the 18.5% resins occurring in Late Cluster or 10 or more percent of the value of the hop has
been lost due to breakage alone. The losses in Early Clusters are only
slightly less. The losses in Fuggles are considerably less in this year's
study, being 2.0331 for machine picked and 0.8400 for hand picked, or an
average of 1.43 for all Fuggles. At 50% whole cones, this would be about
0.72% of the approximate 24.5.
Total soft resins in Fuggles or roughly 5%
of the resins in Fuggles are lost due to breakage alone.
Table 28
Analysis of Variance of Total Soft Resin Differences Between Whole
and Broken-TORT5r all NIETclassificati6E7---Table of Means of Differences
---,kicking
State ---,,
Fuggles
Lachine
Hand
Early Cluster
Hand
MaChiner
Late Cluster
Machine
Hand
California
4.6632 (148)
Idaho
3.9676 ( 42)
Oregon
2.0331 (16) 0.8400 (37) 3.8125 (
3.6762 ( 42) 3,5826 (61)
8)
Washington
3.9873 (113)
umber of observations in parentheses.
4.5827 ( Si)
_
Variation
Due to
Classification
Sum of Squares
Degrees
of
Freedom
Mean
Square
F
Remarks
24,12
**
521.7103
8
65.2138
1326.1671
509
2.7037
Total
1697.8774
4* Significant at 1% level.
517
Error
52
Table 28A
Table of leans
Total Soft Resin
Whole Cone Portion
icking
State -
Fuggles
Machine
Hand
Early Cluster
Machine
Hand
Late Cluster
Machine
Hand
California
18.8148 (148)
Idaho
18.4140(42)
Oregon
13.5625 (16) 15.5773 (37) 17.6400 (
8)
Washington
16.9174 (113)
Number of observations in parentheses.
18.7121 ( 42) 19.8726 (61)
18.6994 ( 51)
Broken Cone Portion
---..kicking
State"---
Fuggles
Machine
Hand
Early Cluster
-Hand'
Machine
Late Cluster
Machine
Hand
California
14.1516 (148)
Idaho
14.4465 (42)
11.5294 (16)
Oregon
14.7373 (37) 13.8275
Washington
12.9302
Number of observations in parentheses.
(
8)
(113)
15.0359 (42) 16.2900
14.1166 (51)
An analysis of variance on alpha resin classified by state for
Late Cluster, machine-picked hops from the four states was calculated
and the results are presented in Table 29. The difference between the
alpha resin contents is significant at the 1% level.
The average alpha
resin content was 6.530, 6.345, 6.140, 6.014 for California, Washington,
Idaho and Oregon, respectively.
Table 29
Analysis of Variance of Alpha Resin Classified by State
Late Cluster, machine-picked hops from California, Idaho, Oregon, and
Washington were used.
Table of Means
California
Idaho
6.140 (42)
6.530 (150)
Number of observations in parentheses.
Oregon
6,014 (42)
Washington
6.345 (51)
(61)
53
Table 29 (Continued)
Variation
Due to
Sum of Squares
State
11.3951
Error
Total
Degrees
of
Freedom
Mean
Square
F
3
3.7984
4.19
254.9337
281
0.9072
266.3288
284
Remarks
Significant
at 1% level
Alpha resin was also classified by variety on machine-picked hops
from Oregon for the varieties 1940.es, Early Cluster and Late Cluster.
The analysis of variance is presented in Table 30.
The differences
between alpha resin contents were significant at the 1% level. The
varieties ranked 6.014, 5.916, 3.906 for Late Cluster, Early Cluster and
Eggles, respectively. This bears out the previous work which showed that
Fuggles was normally much lower in alpha resin content than were the other
varieties.
Table 30
Analysis of Variance of Alpha Resin Classified by Variety
Machine-picked, Oregon hops were used.
Cluster and Late Cluster.
Varieties were Fuggles, Early
Table of Means
Fuggles
Early Cluster
Late Cluster
3.906 (16)
5.916 (8)
Number of observations in parentheses.
6.014 (42)
Degrees
Variation
Due to
of
Sum of Squares
Freedom
Mean
Square
Variety
53.1199
2
26.5600
Error
30.2342
63
0.4799
Total
83.3541
65
F
55.34
Remarks
SignifiCant
at 1% level
Beta resins were also classified by state. The analysis of
variance is presented in Table 31. Late Cluster, machine-picked hops
from the four states were used. The differences between the percent beta
resins were found to be significant at the 1% level.
The average beta
resin content was 10.39, 10.289, 10.119, 9.495 for California, Oregon,
Washington, and Idaho, respectively. California was higher on both alpha
and beta and Idaho was at the bottom of the list in both cases.
54
Table 31
Analysis of Variance of Beta Resin Classified by State
Late Cluster, machine-picked hops from California, Idaho, Oregon, and
Washington were used.
Table of Means
California
Idaho
10.369 (150)
9.495 (42)
Number of observations in parentheses.
Oregon
Washington
10.289 (42)
10.119 (51)
Degrees
Variation
Due to
of
Sum of Squares
Mean
Square
Freedom
State
25.7215
3
8.5738
Error
396.4286
28l
1.4107
Total
422.1501
284
F
6.08
Remarks
Significant
at 1% level
The analysis of variance for beta resin as classified by variety
is presented in Table 32,
Machine-picked hops of the varieties Early
Cluster, Late Cluster and Fuggies in Oregon were used.
The differences
between the varieties were found to be significant at the 1% level.
The
means were 10.289, 9,616, 8.048 for Late Cluster, Early Cluster and Fuggles,
respectively. The rank for beta resin and variety was the same as that
found for alpha, showing that the Late Cluster hop was distinctly higher
in both resins this year tnan were the Early Cluster and Fuggles.
Table 32
Analysis of Variance of Beta Resin Classified by Variety
Machine-picked, Oregon hops were used.
Cluster and Late Cluster.
Varieties were Fuggles, Early
Table of Means
Fuggles
Early Cluster
8.048 (16)
9.616 (8)
Number of observations in parentheses.
Late Cluster
10.289 (42)
55
Table 32 (Continued)
Variation
Due to
Degrees
of
Freedom
Sum of Squares
Mean
Square
Variety
58.2112
2
29.1056
Error
62.1428
63
0.9864
Total
120.3540
65
F
29.51
Remarks
Significant
at 1% level
Total soft resin was also classified by state and by variety.
The
analysis of variance for the classification by state is presented in Table
33. Late Cluster, machine-picked hops from the four states were used in
this analysis. The differences ..n total soft resins were significant at
the 1% level. California was highest with 16.899%, Washington 16.464%,
Oregon 16.303%, and Idaho 15.636%.
Table 33
Analysis of Variance of Total Soft Resins Classified by State
Late Cluster, machine-picked hops from California, Idaho, Oregon) and
Washington were used.
Table of Means
California
Idaho
Oregon
16.899 (150)
15.636 (42)
Number of observations in parentheses.
Variations
Due to
Sum of Squares
Degrees
of
Freedom
Washington
16.303 (42)
Mean
Square
State
56.3230
3
18.7743
Error
1,187.5507
281
4.2262
Total
1,243.8737
284
16.464 (51)
F
4.44
Remarks
Significant
at 1% level
In the previous work on the analyses for resin content, California
hops normally had lower resin content than Oregon and Washington hops.
However, in this year, due to the close relationship established between
the percentage of whole cones and the resin content, these figures possibly reflect more the percentage of whole cones than they do the inherent
differences in the crop. California was much higher in whole cones, .followed
by Washington, Oregon and Idaho, in that order. The resin content also
tends to bear this out,
56
Total soft resin was also classified by variety and the analysis
of variance is presented in Table 34. Machine-picked, Oregon hops were
used for the varieties Riggles, Early Cluster and Late Cluster. As would
be expected from the ranking on alpha and beta resins, Late Cluster is
highest, followed by Early Cluster and then Fuggles. These resin contents,
where the hops are classified by variety, are typical of what has been
found in the past, Late and Early Clusters are normally nearly the same
and it has been recognized for years also that the.FugglEz variety is considerably lower in resin content than the other two varieties.
Table 34
Analysis of Variance of Total Soft Resin Classified by Variety
Machine-picked, Oregon hops were used.
Cluster and Late Cluster.
Varieties were Fuggles, Early
Table of Means
Early Cluster
Fuggles
Late Cluster
16.303 (42)
15.533 (8)
11.954 (16)
Number of observations in parentheses.
Degrees
Variations
Due to
Sum of Squares
Variety
220.4233
Error
Total
Mean
Square
F
2
110.2117
42.89
161.8757
63
2.5695
382.2990
65
of
Freedom
Remarks
Significant
at 1% level
In previous reports, detailed statistical analyses have been presented to show the relationship between certain of these factors on the
resin content. This year correlations and regressions were calculated
and these are presented in Tables 35 to 39 inclusive. Table 35 is presented just to show the distribution of samples in the different classifications. Table 36 gives the regression equation for alpha and beta resins
on the physical factors under consideration. The multiple correlation
coefficient is presented in Table 37. The multiple correlations are
presented both where the classification is ignored and where the values
are corrected for classification. That is, the differences due to state,
varieties, etc., are removed in the corrected by classification multiple
correlation. These multiple correlations were found to be significant
for both resins where the classification was ignored or where it was corrected. The significance is at the 1% level in both cases. This shows
that there is a definite relationship between the physical factors and the
resin content. However, the test of significance for the partial regression coefficient as presented in Table 39 shows that not all factors
that make up this multiple correlation coefficient are significant. The
57
test of significance is presented in Table 39. This table must be used
in conjunction with Table 36 to show whether the relationship is positive
or negative. Since the values corrected by classification are the most
accurate, we will discuss only this table in general.
There seems to be
no significant relationship between the percent seed and alpha resin content, however, as the percentage of seed increased the percentage of beta
resin increased. This is not always the relationship that has been found
in previous work. In some cases a relationship was found with alpha resin
and seed and none with beta and seed, As the percentage of stem and leaf
increased, the percentage of both alpha and beta resin content tended to
decrease. This relationship has always been consistent and demonstrates
the value of cleanly-picked hops. As the estimated amount of lupulin increased, the percentage of alpha resin increased.
There was no significant
relationship between the percentage of beta and the estimated amount of
lupulin. There was no significant relationship established between the
color and condition of lupulin and either resin content.
In some of the
previous work we have found a significant relationship between color and
condition of lupulin and these resins. However, this year's data do not
show that relationship. It should be pointed out, however, that for these
correlations and regressions on color and condition of lupulin, this factor
had only four classifications or ratings, that is, 1, 2, 3, and .4. This
is not enough variation in class for good correlation or regression.
It
is likely that even the four classifications are not too accurate because
the inspectors both agreed that it was very difficult to evaluate the
color and condition of the lupulin this year. Possibly the variation in
classification of this factor was partly responsible for the lack of significance and not that the relationship does not exist.
In view of the
accumulated data and the difficulty of applying this factor, possibly it
would be well to give color and condition less weight in the grading
standards.
Table 35
Distribution of the Number of Samples
---____ in the 2L Different Classifications
Only nine of the 24 possible different classifications contained
sufficient samples for analysis. The following table shows the number
of samples per classification.
-----,Picking
Variety
/ugglSs
early Cluster
Late Cluster
Machine
Machine Hand
Method of
State
-----
Machine
Hand
California
Idaho
Oregon
16
37
Washington
Total
16
37
Hand
Total
150
150
42
42
8
L2
113
51
121
285
61
164
164
61
520
58
Table 36
Multiple Regression Equations
Definition of variables:
yl
:
y2
s
xl
x2
x3
x4
xg
.
:
:
:
:
percent resin A in the entire sample
percent resin B in the entire sample
seed
leaf and stem
lupulin
color and condition
percent whole cones
percent water in the entire sample by the oven method
The following table gives the values of the regression coefficients
for the equations
yl
=
bixi + b2x2 + b3x3 + b4x4 + b5x5 + b6x6 + constant (c)
y2
.
bix1 + b2x2 + b3x3 + b4x4 + b5x5 + b6x6 + c
where the first equation shows the regression of resin A on the physical
analysis and the second equation shows the regression of resin B on the
physical analysis. The table is divided into two parts; the first part
gives the coefficients when the data are corrected by classification and
the second part gives the coefficients when the data are analyzed ignoring
classification.
Analysis
Used
Corrected by
Classification
-----
Ignoring
Classification
Variable.
Coefficient -------7-bl
b
2
yl
0.0122
-0.0753**
Y2
yl
3r2
0.1436**
0.0414**
0.1669**
-0.0670*-
-0.0737*
-0.0651*
b3
0.1664**
0.0153
0.3085:*
0.3890**
b4
0.0552
0.1140
0.1626
0.1782
b5
0.0204**
0.0267**
0.0217**
0.0265**
-0.1413**
-0.1220**
b
6
c
5.5751
* ig
lean at the
level.
*Significant at the 5% level.
2.8982
-0.0715
-0.0250
3.7344
5.708
59
Table 37
Multiple Correlation Coefficients (R)
The following table gives the values of R, the multiple correlation
coefficients for resin A on the physical analysis and resin B on the physical analysis. The total number of samples is 520.
The table gives the
coefficients for the data ignoring classification and corrected by classification.
Table of R
Analysis
Correcte by
Classification
noring
Classification
Resin A
0.3571
0.4801
Resin B
0.4673
0.5597
Variable
Table 38
Test of Significance of Multiple Correlation Coefficients
The significance of the multiple correlation coefficients was
tested by means of the F-test. For F, ignoring classification, the
following equation was used:
R2
F
m
1 - R2
513
with 6 and 513 degrees of freedom.
For F, corrected by classification, the following equation was used:
R2
F
1-R2
505
with 6 and 505 degrees of freedom.
Table of F
Analysis
Used
Corrected by
Classification
Ignoring
Classification
e rees of Freedom
Variable
6 and 505
6 and 513
Resin A
12.30**
25.61**
Resin B
23.52**
39.01**
3 ( Significant at the 1% level.
60
Table 39
Test of Significance of the Partial Regression Coefficients
Since the multiple correlation coefficients were all significant
at the 1% level, the significance of the partial regression coefficients
was also tested. The test used was the F-test. The values of F for each
coefficient are given in the following table;
Table of F
Analysis
Used
Degrees of Freedom
-6'."--'-------..
Coefficient
Corrected by
Classification
1 and 505
Ignoring
Classification
1 and 513
Variable
---------
Resin A
1.01
Resin B
Resin A
Resin B
14.94.**
180.5744*
bl
% seed
b2
% stem and leaf
10.470 *
6.26*
10.9654
6.35*
b
amount of lupulin
10.470*
0.07
37.71**
44.58ii*
b)
color and condition
b
percent whole cones
29.32**
38.08**
% moisture
13.310*
7.52**
3
5
b6
0.43
105.34
3-.38
3.44
59.56-x*
3.26
3.07
66.17**
0.30
e 1p level.
** Significant at
* Significant at the 5% level.
The relation of whole cones to both alpha and beta resins was significant showing that as the percentage of whole cones increased, both
alpha and beta resins increased. This has been pointed out all through
the previous discussion. As the percentage of moisture increased, the
percentage of both alpha and beta resins tended to decrease. While this
analysis for moisture content "shows significance this year, it should not
be regarded as conclusive because previous studies did not establish any
definite relationship between the percentage of moisture and alpha and
beta resins. In fact, there seems to be a trend in the other direction
in some of the previous work, particularly as reported in the 1944-1946
hop grading report. The fact that Table 36 shows that where the classification is ignored there is no significant relationship between the
percentage of moisture and alpha and beta resins would also tend to
create a doubt as to the relationship between moisture and resins.
In much of the previous work total discoloration as a portion of
general appearance has shown no particular relationship to resin analysis.
In many cases fully mature hops will take on a yellow to reddish cast and
be high in resin analysis. However) the trade has always recognized that
discolored hops were difficult to sell in most markets.
In many cases,
these hops have an off-flavor aroma not enough to be unsound or be rated
sample grade, but enough that this factor should be considered in the grade.
63.
This year a correlation of -.3557 was found between general appearance
and alpha resin for Cluster hops. This correlation was significant at
the 1% level. This means that as the grade improved the alpha resin content lowered. This is just about what would be expected in view of the
tendency to harvest the hops immature in order to preserve the uniform
green color. The more mature hops would have discoloration appearing,
but at the same time would have more mature lupulin and consequently
more resin.
It would be well to point out that in some previous studies where
discoloration was due to damage by disease or insects, the total discoloration did lower chemical analysis.
For convenience in comparing the means for these various factors
under the different classifications, the tables of means for the various
factors are presented in Tables 40 to 48 inclusive. These tables of
means are to be used in conjunction with the other statistics discussed
in this section.
Table 40
Table of Means
Seed (X1)
Fuggles
Machine
Hand
Early Cluster
Maehine
Hand
Late Cliaster
Machine
Calif.
4.90
(150)
Idaho
2.82
( 42)
Oregon 11.97
(16) 12.72
(37)
Wn.
6.93
(
8)
8.22
( 42)
1.56
(113)
3.69
( 51)
Hand
9,08
(61)
Table 41
Leaf and Stem (X2)
Early Cluster
Machine
Hand
Fuggles
Hand
MaChine
Late CluSter
Hand
Machine
Calif.
4.43
(150)
Idaho
2.84
( 42)
Oregon
Wn.
Note:
8.08
(16)
6.57
(37)
3.93
(
8)
5.96
( 42)
3.83
(113)
4.49
( 51)
7.12
The number in the parentheses is the number of observations.
(61)
62
Table 42
Lupulin (X3)
Early Cluster
Machine
Hand
Fug
Hand
Late Cluster
Machine
Hand
Calif.
6.2
(150)
Idaho
6.0
( 42)
Oregon
4.5
(16)
5.5
(37)
Wn.
6.8
(
8)
6.2
( 42)
6.2
(113)
5.7
( 51),
(61)
6.44
Table 43
Color and Condition (x4)
Early Cluster
Machine
!Hand
Fuggles
Machine
Hand
Late Cluster
Machine
Hand
Calif.
1.6
(150)
Idaho
1.7
( 42)
Oregon
1.2
(16)
1.3
Wn.
(37)
1.4
(
8)
1.8
( 42)
1.7
(113)
1.6
( 51)
1.8
(61)
Table 44
% Whole Cone (x5)
Fuggles
Machine
Hand
Early Cluster
Lachine
Hand
Late Cluster
Machine
Hand
Calif.
59.4
(150)
Idaho
28.3
( 42)
8)
34.5
( 42) 40.8
(113)
50.1
( 51)
Oregon 20.1
Wn.
Note:
(16) 23.6
(37) 44.1
55.17
(
The number in the parentheses is the number of observations.
(61)
63
Table 45
H2O Oven (X6)
Late Cluster
Machine
Han
-Early Cluster
Machine
Hand
Fu files
Machine
Hand
r-
r-
-
Calif.
8.34
(150)
Idaho
7.62
( 42)
Oregon
8.54
(16)
8.27
(37)
Wn.
8.19
(
8)
8.67
(42)
7.75
4113)
8.47
( 51)
8.83
(61)
Table 46
H2O Dietert (X7)
Early Cluster
Hand
Machine
Fuggles
Machine
Hand
Late Cluster
Machine
Hand
Calif.
8.10
(150)
Idaho
7.18
( 42)
Oregon
8.23
(16)
7.96
(37)
Wn,
8.15
(
8)
8.58
( 42)
7.15
(113)
8.32
( 51)
8.92
(61)
Table 47
Resin A (Y1)
.
niggles
Machine
Hand
Early Cluster
Machine
Hand'
Late Cluster
Machine
Hand
Calif.
6.530 (150)
Idaho
6.140 ( 42)
Oregon
Wn.
Note:
3.906 (16)
5,296 (37)
8)
6.014 ( 42)
5.987 (113)
6.345 ( 51)
5.916
(
6.703 (61)
The number in the parentheses is the number of observations.
64
Table 48
Resin B (Y2)
Fuggles
Machine
Hand
Early Cluster
Machine
-Hand
Calif.
10.369 (150)
Idaho
Oregon
Wn.
Note:
Late Cluster
Machine
Hand
9.495 ( 42)
8.048 (16)
9.731 (37)
9.616
(
8)
9.236 (113)
10.289 ( 42) 11.130 (61)
10.119 ( 51)
The number in the parentheses is the number of observations.
65
SUMMARY
The hop analytical work for the 1949 crop was a joint operation between the Grain Division, Portland Office, PMA and the Oregon Agricultural
Experiment Station. Approximately 600 samples were collected by the FederalState samplers in the four Pacific coast states - California, Oregon, Washington and Idaho. The samples were submitted to the Portland office of the
Grain Division. These samples were divided; one section was separated into
broken and whole cones and these separations were then analyzed for resin
content and moisture determinations were made. A complete series of physical
tests was made on all samples, Upon the completion of the analytical work,
the data were subjected to a detailed statistical analysis, in an attempt
to determine relationship which existed not only-between the various physical
factors,but between physical and chemical factors. During the course of
the investigation, attempts were made to apply the tentative hop standards
(which have been developed in previous work) to determine how effectively
such standards could be used. No attempt has been made to present suitable
standards.
An attempt was made to characterize the 1949 crop in comparison to
those of other years during which the quality had been studied.
The general
appearance of the crop was above normal in that there was less discoloration
and disease because, in general, the poorer segment of the crop was not picked.
There appeared to be more mechanical injury in hops as shown by an increased
percentage of broken cones, particularly in Oregon and California, The Idaho
hops shoed extreme evidence of mechanical damage although no data for this
state are available from former years. There is some evidence that hops were
handled much more rapidly in 1949 than in previous years. Normally, hops are
left in the cooling room for some time after drying.
This year there apparently was a much more rapid movement froM the dryer to the bale than in recent
years. As a resat, the moisture content of hops was not equalized prior to
baling. The hops were therefore, broken somewhat more than in previous years.
The increase in broken cones over the analysis shown in previous years
was striking.. When the tentative hop atandards were applied to the 1949 crop,
only 12 samples of 541 analyzed graded as number one. When the same standards
were applied, but with broken cones eliminated as a grading factor, 121 samples
graded number one. An investigation to determine the effect of present method
of analysis on the amount of broken cones was undertaken. This shows that
the combined effect of using the core sampler, the hop divider as used in
analytical procedure, and the use of' appropriate size screens for broken cone
determination indicated that these factors or procedures were responsible for
an increase in 20% of the broken cones as' shown in the current year -'s analyses.
The matter of technique therefore becomes important in the use of broken cones
as a grading factor and must receive careful consideration if this factor is
to be used in a system of grades.
In earlier studies, distinctions were made between seedless, semiseedless and seeded crops; In the current study, Oregon had 80% seeded hops,
California, 43%, Washington, 1S%, and Idaho, 5%.
The percentage grading semiseedless in the.various states was small; this ranged from 6 to 12%.
The leaf and stem content of hops was lower than in previous years,
With a 5% maximum for tha number oregrade, Oregon had 36%, California, 85%,
Washington, 94% and Idaho, 100% of the samples in the number one grade. Only
small percentages showed more than 8% leaves and stems.
66
When the factor of total discoloration and general appearance was considered, it was found that California had 51%, Washington, 55%, Oregon, 64%,
and Idaho, 97% in the number one grade on this factor.
The amount of lupulin was rather difficult to determine in the 1949 crop.
The analyses show very few thin hops in the 1949 crop, most of these being of
the Fuggles variety. When the tentative standards were used, 2Q% of the
samples would be classed as "thin" hops and 29% would be classed as "fat" hops.
The color and condition of lupulin were satisfactory, although the inspectors found these to be the most difficult of all factors to apply. The
principal difficulty was that the color and condition of lupulin varied from
cone to cone in almost all lots.
There was little damage evident this year. Not one single sample of
Oregon hops was graded down because of mildew. The principal damage found
was mechanical, mold and maturity.
The effect of methods on the determination of broken cones has been
presented. Of the samples examined, it was shovn that for 97% of the Idaho
samples, 93% of the Oregon samples, 53% of the Washington samples and 32% of
the California samples had less than 50% whole cones,
An excellent opportunity was provided to test the accuracy of determining physical factors. Seventy samples were divided into identical pairs and
each one of these pairs was analyzed for physical factors. A statistical
analysis of the results indicates an extremely high degree of reliability in
the application of all factors,
Chemical Investigations - Chemical tests were made of all samples included in the 1949 program. Attempts were made to obtain samples in moistureproof bags. Because of the time element and because of inability to obtain
certain necessary containers, this was not always possible. This in itself
raises a question as to the usefulness of the data on moisture content which
was obtained. It was possible, however, to make tests of certain moisture
testing equipment as applied to hops. The Master Moisture Meter proved to
be unsuitable, The Dietert Moisture Teller was found to be reasonably satisfactory for this purpose when compared with the standard oven method. The
importance of moisture as a grading factor is recognized. What is needed
for moisture testing, however, is equipment which will permit the determination of moisture on the inside of the bale and at a greater depth than can
be reached with the currently used core sampler, Additional work is necessary in order to determine the method and equipment best adapted to this
problem of moisture determination in hops.
From the standpoint of soft resin content, the 1949 hop content in all
four states covered by this work was of better than average quality. Analysis
for soft resin content was made by the colorimetric procedure developed in
previous investigations.
The colorimetric method of soft resin determination is much more rapid
than the official gravimetric method, As a result of previous work, equations
have been used to calculate the percentages of alpha and beta resins. Advantage was taken of the current collection of samples to recheck the equations
obtained in previous work to see if unknown factors might cause variation in
67
them.
The results froM this ye arts study are in close agreement-with those
of previous years. It is believed that the equations obtained from the 1949
data are more accurate than those obtained in previous years.
If soft resins are to be determined chemically in applying grades for
hops, it is suggested that this phase of the investigations be repoeated on
the 1950 crop.
Statistical Analysis of Physical Factors and on the
Relationship Between Physical and Chemicarfactors
The data obtained from the physical analysis were subjected to detailed statistical analyses. These studies show that the differences which
exist in physical characteristics between hops of various states and between
varieties have, for the most part, a high degree of significance.
The correlation between the percentage of the whole cones and the amounts of alpha
and beta resin show that as the percentage of whole cone decreases, the
amount of the soft resin also decreases. There was practically no exception
to this relation. Likewise, significant correlation was found between the
amount of lupulin, color and condition of lupulin and whole cones.
Differences in certain factors are shown by:hops-from the different
states. Oregon hops showed the highest leaf and stem content, Idaho hops
the lowest. The highest estimated amount of lupulin was shown for Oregon
and California hops, the lowest from Washington. The color and condition of
lupulin showed less variation than the amount with, Oregon hops having the
best score. Best condition was shown in the Late Cluster variety, the poorest
in the Fuggles. The Fuggles variety also showed consistently lower soft resin
content than the Cluster varieties. The amount of soft resin varied from
state to state. This variance appears to be associated with the variation
in amount of broken cones.
The relationships that were found between the various factors are
of unusual interest. Some of these agree with previous work, others are at
variance. No significant relationship was found between seed content and
alpha resin; however, beta resin content increased with seed. This is not
fully supported by previous work. As in all previous studies, both alpha
and beta resin tended to decrease as leaf and stem content increased. Alpha
resin tended to increase in proportion to the increase in the estimated amount
of lupulin, although this did not prove to be so with beta resin.
In contrast
to previous work, there appeared to be no significant relationship between
color and condition of lupulin and the amount of soft resin.
(A possible explanation is found in the smaller number of classes estimated and to the unusual character of the lupulin.) The data on the 1949 crop show negative
correlation between discoloration and alpha resin. This is to be expected
as most of the discoloration was the result of maturity.
Previous work shows
that when discoloration was the result of mildew or similar cause, the correlation was positive,
In recapitulation, it appears that certain factors could be added to
those now included in the present official analyses or could be considered
in the establishaent of more definite standards. It has been determined that
these factors do indicate quality (as measured by soft resins) with reasonable
accuracy:
broken cones, damage (mold, mildew, etc.), amount of lupulin, and
within limitS the color and condition of lupulin. (Ilorimetric determination
of soft resins has proved to be a satisfactory method and one which could be
used to handle reasonably large numbers without undue delay.