BELGIAN ACIDIC BEERS
DAILY WELCOME REMINISCENCES OF THE PAST
Hubert Verachtert University of Leuven
Acidic beers
From (1) historic aspects
Through (2) biochemical aspects
To
(3) technical aspects
Acidic beers
Historical aspects
6000 years BC ago, independent of regio’s,it was discovered that
different tasteless milky suspensions of sugary material in water
changed to enjoyable beverages on standing.The magic tool was
spontaneous fermentation.Several types of ”Beer”were invented.Soon
however it was prescribed to consume it rapidly as a vinegar sourness
already known from the souring of grape juice,started to dominate.
Acidic beers were invented.The souring must have been very
common as known from texts such as “..the dead pharaos were
promised bread that doesn’t crumble and beer that doesn’t turn sour”.
(acidic) beers from 6000 BC to 2012
From reeds straws to drink the milky (acidic) beers
avoiding the deposits to cups,bowls,pots and…glasses
!!
Slide 6
Peasant dancing and enjoying
more acidic beer
Slide 7
Medieval brewing
Slide 8
Slide 9
" A green wreath indicated
that the beer was fresh"
Slide 10
Slide 11
ACIDIC BEERS AROUND 1560
FERMENTATIONS QUASI SPONTANEOUS OR
WITH added FOAM "INOCULA" FROM PREVIOUS BATCHES
LOW ATTENUATIONS and ALCOHOL CONTENT
THE BEERS ARE OPAQUE
UNAVOIDABLE BACTERIAL INFECTIONS FORM ACIDS
- during wort cooling
(lactic acid )
- during mashing - in
(lactic acid)
- during storage
(lactic + acetic acid)
INFECTIONS INTRODUCED FROM THE AIR, RAW
MATERIALS,EQUIPMENT and INOCULA
Depending on region use of barley + wheat. Rye leads to “beer vinegar”
HOPS BETTER THAN HERBS AGAINST HIGH ACIDIFICATIONS
Slide 12
The famous beers of Louvain
the Peterman and
the Bière de Louvain (18 -20 century)
th
th
Peterman (yellow-brown)
Bière de Louvain (white)
barley + wheat
Acidity fresh beer 600 ppm (as lactic acid)
Old beer up to 4000 ppm
Alcohol :around 3 %
STATEMENTS CONCERNING
BEER ACIDIFICATION AND WORT ATTENUATIONS
(1895-1905)
" HIGH ATTENUATION LEADS TO HIGH ALCOHOL LEVELS WHICH KILL THE YEASTS ,
NEEDED DURING STORAGE TO FAVORABLY COMPETE WITH BACTERIAL INFECTIONS "
" HIGH ATTENUATED WORT CONTAINS RESIDUAL SUBSTRATES WHICH CAN ONLY BE
USED BY NON-YEAST INFECTIONS "
CONSEQUENTLY KEEP THE ATTENUATION LOW :
" TURN TO BARLEY KILNING OR RE-KILNING TO REDUCE
ITS DIASTASIC POWER AND INCREASE THE FERMENTABLES
CONTENT OF THE WORT "
" USE THE TURBID MASH BREWING METHOD "
" INCREASE WORT AERATION TO PRODUCE MORE YEAST AND
REDUCE NITROGENOUS COMPOUNDS "
" USE MORE NON - MALTED GRAINS "
Slide 14
Optimal lactic acid acidity of acidic beers advized by
H.Verlinden (brewmaster in Brasschaat) around 1930
calculated from NaOH titration values
White beers of Louvain:
Antwerp,Brabant,Limburg:
Flanders beers:
Lambics:
1800 ppm
2700 ppm
4500 ppm
9000 ppm
Main Problem: how to control the concentration of
acetic acid (bacteria)!!!
For lambics remain under the 1000 ppm limit.
Slide 15
More old acidic beers in
Het Hageland
Hoegaarden,Aarschot,Tienen,
Diest…
All involve a type of spontaneous fermentation in casks
Folklore : yearly « Grietmuyl » celebration in Tienen
« Grietmuyl »: Refers to the awful mouth of brill fish
(=griet=kind of turbot).Sometimes…
a drinker at a first sip of a Hoegaarden showed
a sour face… It indicated that the beer was
turning to vinegar,meaning the beer
was an acidic beer which
according
to indications had to be drunk before
summertime.
Slide 16
SPARKLING ACIDIC BEERS
AT THEIR BEST...
MEETING POINTS BEWEEN BEER AND WINE
AT THEIR WORST ...
A TASTE OF HISTORY
17
Slide 17
Acidic beers
Biochemical aspects
ACETIC ACID PRODUCTION from ethanol BY ACETOBACTER
energy for growth=oxidation of ethanol with O2 to acetic acid!!
CH3-CH2OH + NAD+ > CH3-CHO + NADH + H+ with membrane dehydrogenase !
CH -CHO+ NADP+ >CH -COOH + NADPH + H+ with membrane dehyrogenase!
3
3
Transport of electrons and protons from reduced co-enzymes to oxygen:
NADH >>electrons >>>> O >> H O + trans membrane proton gradient >>ATP synthesis
2
2
Growth on ethanol by Acetobacter
Growth = from ethanol through acetate and
acetyl-CoA (c-2) and through malate (c-4) and the
glyoxylate cycle
2 acetyl-CoA (2 C-2) >> malate (C-4) + 2 CoA
then:malate>>oxalacetate>>pyruvate>>sugars
Unraveling the lactic acid acidification
Centuries ago:appreciated in milk,not in beer!
1780 Scheele: lactic acid isolated from milk
1873 Wislicenus:acid=CH3-CHOH-COOH
1876 Pasteur:acid=biological origin (rods+cocci)
1878 Lister:name Bacterium lactis
1892 Van Laer:Saccharobacillus
1901Beijerinck:Lactobacillus
1812 Goodsir:Cocci Sarcina (latin=bundles)
1884 Balcke:Pediococcus (latin cells in a plane)
Acetification by Brettanomyces
Brettanomyces:fermentation=stimulated by O2
but leads to acetic acid !!(Scheffers,1966)
glucose+NAD++NAD+ ==)) CH3-CHO+NADH++H++CO2
==)) CH3-CHO+NADH++H++CO2
CH3-CHO+NADH+H+=))CH3-CH2OH+NAD+ (alcohol dehydrogenase)
CH3-CHO+NAD+=))CH3-COOH+NADH+H+ (aldehyde dehydrogenase)
Glucose+2 NAD+=))CH3-CH2OH+CH3-COOH
+2
NADH + 2 H+ + 2 CO2
Excess NADH stops further glucose metabolism
Oxygen regenerates needed NAD+
!!!!!Fermentation resumes!!!!!
Types of Belgian beers
Trappist ales (strong, with yeast deposit, brewed in abbeys)
Abbey ales
(strong, with /without yeast deposit, not brewed in abbeys)
Ales and strong ales (different colours, with/without yeast deposit)
Pilsner types
White beers (barley+wheat+spices,turbid)
ACID ALES and FRUIT BEERS
Slide 24
Acidic beers
technical aspects
Belgian lambics
and gueuzes
Belgian acidic beers anno 2012
-2 main types1.spontaneous fermentation:lambic
and gueuze
2.yeast-bacterial mixed culture
fermentation
sparkling acidic
beers
At their best...
Meeting points between
beer and wine
At their worst…
A tast of history
Where lambic and gueuze are produced
(more recent :lambic types in West
Vlaanderen:Ingelmunster and Bellegem)
Slide 28
LAMBIC : (end 18 th century) from alambics
found in breweries also making spirits
GUEUZE : gueuze = some old lambic sold in
bottles
>>>with time bubbles and foam production observed
>>>cheap used champagne bottles available (begin 19th
century)
>>>Champenoise method known and competition from
sparkling new pilsner beers
>>>improve lambic sparkling by blending old lambic
with young lambic
>>>good bottled lambic first sold
in 1844 as gueuzelambic by some breweries.
what’s in a name?
Gueuze not mentioned in standard work of G.Lacambre in
1851
Slide 29
CHARACTERISTICS
OF TRADITIONAL LAMBIC BREWING
RAW MATERIALS : BARLEY +
HOP :
WHEAT
AGED HOP CONES / HIGH DOSIS
BREWING: TURBID MASH
FERMENTATION :
PRODUCTION :
SPONTANEOUS
COLD SEASON
SELECTED REGIONS
Slide 30
Filling of open shallow trays
Slide 31
Cooling
Slide 32
Turbid mash method
(slijmmethode)
Mash at 38°C (10 min)
Proteinrest at 50°C (15 min)
warm up until 63°C
hot water addition to
take slime
heat separately
until 80-90 °C
warm up until 72°C
α-amylaserest at 72°C until iodine normality
direct the hot slime
to the mash
filtration and sparging at 78°C
go to the kettle
Slide 33
The so called madammen
(madams)
A typical device of rotating
perforated discs used by lambic
brewers to filter the mash
Slide 34
Traditional gueuze brewing
from bags of grain to glass
Wooden casks (300-8000 L)
cask filling
Slide 36
Wooden casks (300-8000 L)
Slide 37
Wooden casks (8000 L)
Slide 38
Slide 39
Slide 40
Large metal tanks
Slide 41
Main lambic yeasts
-1. Saccharomyces and typical
Brettanomyces sp.
-2. Discovered in old English stock beer and named
Brettanomyces in 1903 by Claussen (Carlsberg
Laboratories)
-3. Discovered in lambic in 1921 and named
Br.bruxellensis by Kufferath and Van Laer
-4. Gives typical Brett flavour consisting of
e.g.ethylphenol,ethylguaiacol,isovaleric acid,acetic
acid,ethylacetate ,2-acetyl 1,4,5,6 tetrahydropyridine and
ethyllactate
-5. Ferments higher oligo-saccharides !
Slide 42
Brettanomyces present in all
acidic beers ?
Prefer acidic conditions established by lactic acid
(and acetic ?)bacteria
Actually 5 Species
Br.bruxellensis,intermedia,intermedium,lambicus,custersii
=Brettanomyces (Dekkera)bruxellensis
Br.abstinens,claussenii,anomalus
=Brettanomyces(Dekkera) anomala
Brettanomyces naardenensis
Brettanomyces custersianus
Brettanomyces nanus
The famous Brettanomyces
and Pediococcus
Slide 44
Lambic fermentation microbiological profile
Comparison of
different brewing and fermentation
conditions
METAL TANKS versus WOODEN CASKS
INFUSION versus TURBID MASH BREWING
FRESH versus OLD HOP / TURBID MASH
FRESH versus OLD HOP / INFUSION
DIFFERENT WORT AT SAME LOCATION
SAME WORT AT 2 DIFFERENT LOCATIONS
(data from G.Aerts/Kuleuven/Kaho)
Slide 46
Lambic characteristics determined during
18 months lasting fermentations
ENTEROBACTERIACEAE (normally found /first weeks)
ACTIDIONE-RESISTANT YEASTS ( Brettanomyces)
NON ACT.-RES. YEASTS (e.g. Saccharomyces)
LACTIC ACID BACTERIA
ATTENUATION
ETHANOL
LACTIC ACID
ACETIC ACID
pH
ETHYL LACTATE
ETHYL ACETATE
Slide 47
WHATEVER CONDITIONS EXAMINED :
Microbial Sequence in lambic fermentation
Enterobacteriaceae sp
Saccharomyces sp + LAB sp
Brettanomyces sp + LAB sp
Slide 48
METAL TANKS versus WOODEN CASKS
2
4
6
8
10 12 14 16 18 20
1500
140
120
100
80
60
40
1250
1000
750
500
250
20
0
0
0
2
4
6
8
10 12 14 16 18 20
ETHYLACETATE –- PPM
PPM
ETHYLACETATE
0
ACETATE -–PPM
PPM
ACETATE
700
600
500
400
300
200
100
0
7450
6450
5450
4450
3450
2450
1450
450
Acetate ( ACET ) + ethylacetate ( E.ACET )
ETHYLACTATE –- PPM
ETHYLLACTATE
PPM
LACTATE- PPM
– PPM
LACTATE
Lactate ( LACT ) + ethyllactate ( E.LACT )
MONTHS
MONTHS
MONTHS
WOOD –- LACT.
WOOD
LACT.
METAL –- LACT.
METAL
LACT.
WOOD –- ACET.
ACET.
WOOD
METAL -– ACET.
ACET.
METAL
WOOD –- E.LACT.
WOOD
E.LACT.
METAL –- E.LACT.
METAL
E.LACT.
WOOD –- E.
E.ACET.
WOOD
ACET.
METAL -– E.
E.ACET.
METAL
ACET.
Turbid mash method / old hop / comparison between metal tank and wooden cask
WOOD
METAL
Original extract
°P
9.8
9.8
Final attenuation (app)
%
93 . 1
97 . 2
Final attenuation (real)
%
74 . 4
78 . 6
3.3
3.1
pH
Slide 49
Lambic fermentation microbiological profile
Lambic fermentation:Brettanomyces type yeasts,actidione resistant
tanks:wood vs metal
hops:fresh vs old
METAL TANKS versus WOODEN CASKS
Actidione resistant yeasts ( A. Res. Y. ) +
Non
actidione resistant yeasts ( Non A. Res. Y. )
8
7
6
5
4
3
2
1
0
LOG N c.f.u./mL
c.f.u./mL
LOG
0
2
4
6
8
10
12
14
16
18
20
8
7
6
5
4
3
2
1
0
0
2
4
6
8
MONTHS
MONTHS
METAL
METAL -– ENTERO'S
ENTERO’S
WOOD –- LAB.
WOOD
LAB
METAL –- LAB.
METAL
LAB
5
°P
°P
15
4
10
3
2
5
1
0
0
8
10
12
14
16
18
20
MONTHS
WOOD –- °P
WOOD
WOOD –-ETH
ETH
WOOD
WOOD –- pH
WOOD
LOG
LOGNNc.f.u./mL
c.f.u./mL
6
6
16
18
20
Lactate ( LACT ) + Lactic acid bacteria ( LAB )
ETH(%
(% v/v)
v/v) and pH
ETH
pH
20
4
14
METAL –- A. RES.
RES. Y.
METAL
Y.
METAL -– NON
NON A.
METAL
A. RES.
RES.Y.Y.
WOOD -– A.
A. RES.
RES. Y.
WOOD
Y.
WOOD -– NON
NON A.
WOOD
A. RES.
RES.Y.Y.
Eapp ( °P ) + ethanol ( ETH ) + pH
2
12
MONTHS
MONTHS
WOOD
WOOD –- ENTERO'S
ENTERO’S
0
10
8
7
6
5
4
3
2
1
0
8000
7000
6000
5000
4000
3000
2000
1000
0
0
2
4
6
8
10
12
14
16
18
LACTATE -–PPM
PPM
LACTATE
LOGN
N c.f.u./mL
c.f.u./mL
LOG
Enterobacteriaceae ( ENTERO’S ) +
Lactic acid bacteria ( LAB )
20
MONTHS
MONTHS
METAL -– °P
°P
METAL
METAL
–
ETH
METAL -ETH
METAL -–pH
pH
METAL
WOOD –-LAB.
WOOD
LAB
METAL – -LAB.
METAL
LAB
WOOD –-LACT.
WOOD
LACT
METAL – -LACT.
METAL
LACT
Slide 52
Under proper conditions
•
• Lambic can be
produced in metal
tanks
Under proper conditions
•
• Fresh hops
compared to aged
hops were not
detrimental to
lambic brewing
Under proper conditions
• Infusion
brewing
compared to
turbid mash
brewing is
possible
Under proper conditions
• Infected lambic
worts from site
A or B give a
good similar
cask fermenting
lambic at site C
Under proper conditions
•
• Seeded lambic
wort at site A
shows a similar
behavior when
cask fermented at
different sites a
or b
Spontaneous infected lambic wort
from a brewery A is transfered to
brewery a and b where it is only
cask- and bottle fermented.
Or:the infected worts from brewery A
and B is transfered to brewery a
OBSERVATIONS:
The cask environment has more final
effects than the open trays
environment
The steker gueuze has its own
characteristics.
Slide 59
Bottle refermentation scheme
CLASSIC BOTTLE
REFERMENTATION
TRADITIONAL LAMBIC
BOTTLE REFERMENTATION
YOUNG FINISHED BEER
OLD LAMBIC
(enzymes + micro-organisms)
MIXED WITH YOUNGER
LAMBIC (substrates)
ADDITION OF SUGAR + YEASTS
BOTTLING
INCUBATION
REFERMENTED BEER
BOTTLING
INCUBATION
GUEUZE (« FOND GUEUZE »)
Slide 60
Slide 61
Experimental conditions
to study bottle refermentations
4 MOTHER LAMBICS
A - 20 months (0.95°P)
D - 20 months (2.28°P)
B - 12 months (3.10°P)
F - 20 months (1.99°P)
AND
10 DIFFERENT MICROBIAL INOCULATIONS
Brettanomyces bruxellensis
Brettanomyces lambicus
Saccharomyces cerevisiae
Saccharomyces bayanus
Pediococcus (2 strains)
Brettanomyces (isolated, 2 strains)
A
x
B
C
D
E
x
x
F
x
G H
x
x
I
J
x
x
x
x
x
x
x
x
x
Slide 62
Other gueuze beers
1.Filtered gueuzes: lambic
pasteurized,notrefermented,carbonated (sweetened)
2.Fruit beers: As above but
mixed (diluted) with fruit juices.(Not
always with lambic)
3.Kriek gueuze: cask-fermented
with added sour cherries and
refermented:The real thing!)
Slide 63
FARO
much preferred sweetened version of lambic
Faro from latin far:a type of wheat
Faro is a blend of old strong lambic
and a less strong version.The blending
is traditionally done by the inn-keeper
or later by the brewer or
a »préparateur »,an intermediate
between brewer and inn-keeper
Anyhow the blend is sweetened by
the inn-keeper by adding dark
concentrated lambic wort syrup or later
candy sugar.The préparateur in
general may clarify,colour and sweeten
the faro blends….
Slide 64
Preferential sweetening of acidic beers
Faro is a lambic locally sweetened by pub holders
Sweetening can also be an individual preference.An
individu is then provided with sugar and a crusher
(“stoemper”)This practice was also common for other
acidic beers such as Aarschotse bruine etc.
2.Acidification by blending an ale with lambic or gueuze
JACK-OP !!!
.
A succesful acidic beer around
1920 ,brewed in Werchter ,
called the students beer, is a BLEND of a top
fermented ale and a lambic or gueuze.
A similar process was used for Aarschotse bruine
which has recently been re-introduced.
Are white beers acidic ?
Verlinden in 1944 described our white beers to
contain around 2000 ppm acid (as lactic acid)NOW in
contrast to the German Berliner Weisse(+mixed
cultures)
the Belgian white beers(+pure cultures) are not
really sour
(although drinkers may appreciate sourness by
adding a slice of lemon!)
A so called white lambic on the contrary can be
appreciated by its charming low acidity
Lambic wort+spices--spontaneous fermentation-young lambic--carbonatation--bottling-pasteurisation
THE FUTURE OF
LAMBIC AND GUEUZE
SPONTANEOUS FERMENTATION CAN SURVIVE
BY USING TIME SAVING PROCESS ADAPTATIONS
WHICH DO NOT LARGELY AFFECT
THE REQUIRED CHARACTERISTICS OF THE FINAL REAL PRODUCT
FOR RELIABLE ADAPTATIONS HOWEVER
A MINIMUM OF SCIENTIFIC KNOWLEDGE
BECOMES A NECESSITY
Slide 68
Acidic beers
Belgian red and brown
sour ales
Non gueuze TYPES OF ACID BEERS
ANNO 2012
The regional Flandres acid ales
type Rodenbach….
Slide 70
Rodenbach,Liefmans,Petrus,Bacchus,Bourgogne
des Flandres,Duchesse de Bourgogne…
Red-brown Flandres acidic beers fermented in barrels or
metal tanks.
1. Flanders' red-brown beer : Rodenbach
Large wooden casks
Slide 72
Rodenbach beer fermentation steps
WORT
“yeast”
7 d 16 - 21°C
PRIMARY FERMENTATION
CYLINDRO CONICAL
TANK
a
EPOXY COATED TANK
young beer
CASK
▼
aged beer
►
SECONDARY FERMENTATION
4 - 5 W 15 - 21°C
TERTIARY FERMENTATION
18 – 24 M 15 - 21°C
on-line blending
to GRAND CRU
to RODENBACH
◄◄◄◄◄◄
◄◄◄◄◄◄
cooling 0°C ► centrifugation ► carbonatation ► pasteurization
Slide 73
Evolution of microbial populations
of Rodenbach fermentation
Log (CFU / mL)
: total yeasts
: actidione-resistant
yeasts
: lactic acid bacteria
: acetic acid bacteria
9,00
8,00
7,00
6,00
5,00
4,00
3,00
2,00
1,00
0,00
Log (CFU/mL)
0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 5 5,5 6 6,5
9,00
8,00
7,00
6,00
5,00
4,00
3,00
2,00
1,00
0,00
Weeks
0
10
20
30
40
50
60
Weeks
70
80
90
100 110
Slide 74
Evolution of lactic acid during
Rodenbach fermentation
Lactic acid (ppm)
900
: total lactic acid
: D lactic acid
: L lactic acid
750
600
450
300
150
0
0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 5 5,5 6 6,5 7
Weeks
Lactic acid (ppm)
6000
5000
4000
3000
2000
1000
0
0
10
20
30
40
50
60
70
80
90
100 110
Weeks
Slide 75
Evolution of acetic acid during
Rodenbach fermentation
Acetic acid (ppm)
1200
1000
800
600
400
200
0
Acetic acid (ppm)
0
0,5
1
1,5
2
1600
1400
1200
1000
800
600
400
200
0
0
10
20
30
40
50 60
Weeks
70
80
90
2,5
3 3,5
Weeks
4
4,5
5
5,5
6
100 110
Slide 76
6,5
CONCLUSIONS
The renewed appreciation for high quality
gueuzes and sour ales proves that
traditional processes
CAN survive modern times provided that
the brewer is prepared for
HARD WORK , incomparable enthusiasm
for the final product and awareness and
understandig of possible scientific progress.
Slide 77
TYPES OF ACID BEERS ANNO 2009
BERLINER WEISSBIER (Germany)
Slide 78
Goslar/Leipzig Gose
beer
Spontaneous fermented acidic
beer around 1740
Cask fermentation achieved in
long neck bottles
Bottles closed by yeast
crop,not corked !
Slide 79