Example assessment & marking criteria
Assessment type:
Practical workbook and summary
Subject:
WSC304 Wine Chemistry
This subject is a study of the application of chemical principles to wine stability. Wine stability includes the study of
bentonite fining, protein and PVPP fining agents, fining with copper ion, blue fining, potassium hydrogen tartrate
precipitation, ion-exchange processes, polysaccharides and the use of enzymes in winemaking.
 be able to successfully use chemical principles to interpret and assess the impact of winemaking conditions on
wine stability;
 be able to demonstrate how and why chemical principles influence the task of fining and stabilising wines, and
be able to demonstrate this awareness in their selection of fining agents and interpretation of their performance;
 be able to demonstrate competence in the performance and interpretation of fining trials;
 be able to demonstrate an understanding of the action of enzyme treatments used in winemaking, particularly
enzymes of microbial origin.
Subject learning
outcomes:
Assessment task:
Value& length:
Task description:
2. Practical workbook and summary
30%, Workbook-no limit, Summary-4 pages (double spaced)
In the residential school, you have the opportunity to perform fining trials on wine samples; typically, a low quality
white wine and a phenolic red wine. You need to:
 Assess the wine's sensory features and perform chemical analysis (pH, TA, SO2) to identify their condition, the
existence of any faults, their potential quality, and the likely actions that may improve their quality.
 Identify a 'plan of attack' to improve the quality of the samples. Include, as required, chemical adjustment of pH,
TA, SO2, tests for protein stability and protein level, fining with bentonite, copper, protein fining agents and
PVPP, and the possible need for tannin or silica sol addition in the fining. Make that plan widely exploratory,
rather than narrowly focussed, where possible. Thus, if you plan to use gelatin, consider also trying for example,
isinglass, casein, egg white and PVPP, to provide comparative data.
 Systematically perform chemical adjustments and fining trials. Use sensory assessment of the fined samples to
judge their effect. Seek to gain the greatest improvement in the sample quality, refining the 'plan of attack' as
required to incorporate experimentally-derived findings. Expect, in the time available, to be able to tackle,
typically, one wine in detail, and one other wine in lesser detail.
 As the work is done, report your thoughts, plans, calculations, actions and findings in your work notebook.

Rationale:
Attempt to do this in a way that would allow a third person, upon reading your book, to immediately understand
what you have done, why you did it, how you did it, and what you found.
Summarise (either in your work notebook or separately, if word-processed), your findings, after completion of
the work. This requires a brief but thorough summary of the initial sample conditions, your planned strategy, the
key outcomes, your interpretation of those outcomes (e.g. why did something work, or not work), and your
conclusion as to the potential for improvement of the samples. Use the assessment criteria below as a guide.
The summary should be written as if it were to be submitted to an experienced winemaker (with comprehensive
knowledge on wine production and the associated underlying theories of wine fining and stabilisation).
Further information about reporting your work and writing your summary will be given at the residential school.
Fining trials are an important part of the winemaking process. Their success requires integration of the sensory
assessment of the wine with an understanding of the mechanisms of fining agent actions, a structured, investigative
approach to the trial, and an awareness of the potential end-market for the wine.
The practical work seeks to:
 Provide you with the opportunity of performing fining trials in which your sensory skills, your wine chemistry
knowledge, your end-market awareness, and your investigative approach can be developed and demonstrated.
 Encourage you to link the teaching material of Study Guide 1 and the Practical Manual to real wine production
situations.
 Assess your ability to perform fining trials in a structured, investigative manner, and to report the findings in a
logical, clear and communicative way.
Marking criteria & standards of performance
CRITERIA
Criteria 1:
Sensory
assessment of
wines and overall
strategy for the
production of
finished wine.
(10 marks)
Criteria 2:
Reporting of the
experimental
procedure and
findings in a
laboratory
workbook.
(40 marks)
Pass
A strategy is outlined for
finishing the wines with a
vague link to the sensory or
chemical data. The strategy
shows basic considerations of
the chemical principles behind
the action of at least one fining
agent and at least one
stabilisation procedure. No
consideration is made of
exploratory work.
The reporting in the laboratory
workbook identifies
comparisons and most
optimum fining levels. More
often than not, it provides
calculation examples, dilution
procedures, fining agent
preparation conditions,
sampling handling/storage
conditions and individual
sample sensory assessments.
At least half of the laboratory
work book is of sufficient detail
to allow a third-party to repeat
the work. The range of
stabilisation and fining trials
performed was only just
appropriate for the time
available.
STANDARDS
Credit
Distinction
A strategy is outlined that links A strategy is clearly outlined that
to the tasting notes for the
links well to the tasting notes for
wines and the provided
the wines and the provided
chemical data. The strategy
chemical data. The strategy
shows some considerations of describes some considerations of
the practicalities of wine
the practicalities of wine
production as well as the
production as well as the
chemical principles behind the chemical principles behind the
action of at least 2 specific
action of at least 2 specific fining
fining agents and on the
agents and on the stabilisation of
stabilisation of wine. No
wine. It also highlights planned
consideration is made of
actions that are more exploratory.
exploratory work.
The reporting in the laboratory
workbook identifies
comparisons and most
optimum fining levels. More
often than not, it provides
calculation examples, dilution
procedures, fining agent
preparation conditions,
sampling handling/storage
conditions and individual
sample sensory assessments.
At least half of the laboratory
work book is of sufficient detail
to allow a third-party to repeat
the work exactly. The range of
stabilisation and fining trials
performed was more than
appropriate for the time
available.
The reporting in the laboratory
workbook presents reasons for
actions, identified comparisons
and identified optimum fining
levels. It provides the vast
majority of calculation examples,
dilution procedures, fining agent
preparation conditions, sampling
handling/storage conditions and
individual sample sensory
assessments. The laboratory
work book is of sufficient detail to
allow a third-party to repeat the
work exactly. The majority of the
reporting, of work performed, was
completed at the time of the
experimental work. The range of
stabilisation and fining trials
performed was appropriate for
High Distinction
A strategy is clearly outlined that
links well to the tasting notes for
the wines and the provided
chemical data. The strategy
describes complex and
extensive considerations of the
practicalities of wine production
as well as the chemical
principles behind the action of a
selection of specific fining
agents and on the stabilisation
procedures for the wine. It also
highlights planned actions that
are exploratory rather than
necessary.
The reporting in the laboratory
workbook presents reasons for
actions, clearly identified
comparisons and identified
optimum fining levels. It provides
calculation examples, dilution
procedures, fining agent
preparation conditions, sampling
handling/storage conditions and
individual sample sensory
assessments. The laboratory
work book is of sufficient detail
to allow a third-party to repeat
the work exactly. The reporting,
of work performed, was
completed at the time of the
experimental work.
The range of samples and fining
trials performed was appropriate
Criteria 3: Overall
summary of
laboratory
workbook.
(proposed
audience of
summary:
winemaker
colleagues)
(30 marks)
Criteria 4: Final
recommendations
for wine (within the
Summary of the
laboratory
workbook)
(20 marks)
The reporting shows some
significant shortcomings that
suggest a confused and
uncertain approach to the
work. Some work conducted
was not appropriately
targeted.
The summary provides
description of either the initial
tasting or chemical analysis
data. It outlines the strategy
for treatment of the wines
without clear justification. The
summary identifies most
actions taken and their
principle outcome. The
summary contains some
errors in the reporting of work
performed and in grammar,
and doesn’t make specific
reference to pages of the
laboratory workbook.
Final recommendations are
provided that establish the
type of wine style for which the
wine is designed. Appropriate
wine fining treatments are
proposed for this wine style
based upon consideration of
the laboratory work outcome.
No mention is made of the
price-point of the wine.
The reporting shows a few
errors or omissions but most
aspects are soundly tackled.
Some work was not
appropriately targeted.
the time available, and the range
of work allowed some exploratory
trials.
for the time available, and the
range of work was both
appropriately targeted, yet
exploratory in at least some
instances.
The summary provides
description of the initial tasting
and chemical analysis data. A
strategy for treatment of the
wines was proposed and was
loosely justified on either
theoretical or practical
grounds. The summary
identifies the majority of
actions taken and their
principle outcome. The
summary links to the
laboratory workbook on a few
occasions, with page
references for key actions.
Final recommendations are
provided that establish the
type of wine style for which the
wine is designed. Appropriate
wine fining treatments are
proposed for this wine style
based upon consideration of
the laboratory work outcome
and the price of the fining
agents. No mention is made of
the price-point of the wine.
The summary provides tabulation
of the initial tasting and chemical
analysis data. An appropriate
strategy for treatment of the
wines was proposed and was
justified on either theoretical or
practical grounds. The summary
identifies all actions taken and
their principle outcome. It links to
the laboratory work book with
page references for key actions.
The summary provides
tabulation of the initial tasting
and chemical analysis data and
a brief descriptive overview
given of the main points. An
appropriate strategy for
treatment of the wines was
proposed and was justified on
theoretical and practical
grounds. The summary
identifies all actions taken and
their principle outcome. It links to
the laboratory work book with
page references for key actions.
Final recommendations are
provided that establish the type of
wine style and price point for
which the wine is designed.
Appropriate wine fining
treatments and stabilisation
treatments are proposed for this
wine style and price point, based
upon consideration of the
laboratory work outcome and
economic considerations.
Final recommendations are
provided that establish the type
of wine style and price point for
which the wine is designed.
Appropriate wine fining and
stabilisation treatments are
proposed for this wine style and
price point based upon detailed
and extensive consideration of
the laboratory work outcome,
subject theory and economic
considerations.