Transcript High Alcohol Fermentations: How to Manage Primary and

High Alcohol Wines: How to
Manage Primary and Secondary
Fermentation
Presented by:
Jessica Just of Scott Laboratories
and
Sigrid Gertsen-Briand of Lallemand
Winemaking Goals in a High Sugar
Ferment
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Convert all sugar to alcohol
Minimize the production of volatile acidity
Minimize volatile sulfur off-aromas
Balance % alcohol with phenolic maturity
Complete the malo-lactic conversion in a
timely manner
• Minimize microbial deviations
Yeast
Glucose
CO2
Ethanol
Esters
H+
Internal pH is 5-6
H+
Glycerol
Organic Acids Higher Alcohols
Biomass (≈ 2% glucose)
H+
H+
External pH is 3-4
>100-150
million
CFU/mL
Population
Normal Fermentation Curve
Higher yeast inoculation rate
lowers dilution of the initial yeast
cells survival factors
4-8 million
CFU/mL
million
2-42-4million
CFU/mL
CFU/mL
Time
Brix
Survival factors are important to ensuring the proper
working of the cellular membrane: poly-unsaturated
fatty acids and sterols
Key Interrelationships of Factors
Affecting Fermentation
SUGAR CONTENT
TEMPERATURE
CELL
NUMBERS &
HEALTH
STRAIN
SELECTION
MAXIMUM
FERMENTATION
MANAGEMENT
TOXIC
FACTORS
NUTRIENTS and
OXYGEN
COMPETITIVE
FACTORS
Temperature Control in Red Must
Max. Temperature
Cap
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20 Brix
21 Brix
22 Brix
23 Brix
>24 Brix
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95°F
90°F
85°F
80°F
76°F
What to Know Before Restarting a
Stuck Alcoholic Fermentation
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Total residual sugar
Glucose:Fructose ratio
What caused the stuck fermentation
Which yeast strain was used for the initial
fermentation
• Temperature control
Dealing with a Stuck Alcoholic
Fermentation
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Refer to websites for actual protocols
Blend
Sterile Filter
Long acclimatization, build-up with sugar
Short acclimatization with high inoculation rate
How many times should you try to restart a stuck
ferment? When can you start tasting the yeast?
• Use of yeast hulls
• Addition of nutrients?
Alcohol content (% v/v) reached after fermentation in white
wines with 56 selected Saccharomyces cerevisiae yeasts
that were able to ferment all sugars.
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11
Grado alcohólico adquirido (%)
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9
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6
5
4
3
2
1
0
Productor 1
Productor 2
Productor 3
Productor 4
Productor 5
Productor 6
Alcohol content (% v/v) reached after red vinifications with
35 selected Saccharomyces cerevisiae yeasts that were
able to ferment all sugars.
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15
14
Grado alcohólico adquirido (%)
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10
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5
4
3
2
1
0
B1
B2
B3
B4
C1
C2
D1
D2
D3
D4
D5
E1
E2
E3
E4
Productor 1
Productor 2
E5
E6
E7
E8
E9 E10 E11 E12 E13 E14 E15 E16 E17 E18 F1
Productor 3
Productor 4
Productor 5
Productor 6
F2
F3
G1 G2 G3
phosphoketoslase
pathway
(Heterofermentative)
Citrate
BACTERIA Acetate
WINE
Oxaloacetate
L-Malate
Mannoprotein
L-lactate
More efficient
malic acid
degradation
0.1-0.2 units
increase in pH
(palate)
Pyruvate
Diacetyl
Polysaccharides
b (1->3) glucanse
Growth & stimulation of MLF
Protein
Bitterness ?
flavour
Sugar + flavour-aglycon
Ethanol
Increase in aroma
Cell growth
Citrulline, urea
Ethyl
Mousy
Ethyl
lactate compounds carbamate
Off-flavour
carcinogen
Mouthfeel
contribution
Pentoses
pentose
phosphate
pathway
Sugaranthocyanin
glycosidase
(anthocyanase)
Sugar + anthocyanidin
Adsorption by
cells
Cell growth
SO2-acetaldehyde
Bruised apple
(green, vegetative)
Acetate & ethanol &
free SO2
Glycerol
&
erythritol
Mannitol
Ethylesters
esterase
ethyl lactate, ethyl
acetate, ethyl
hexanoate, ethyl
Colour reduction
octanate
b -glucosidase
Peptides
Esters
synthesis & hydrolysis
Sucrose, trehalose
phenolic glucosides
Glycoside (flavour)
protease
Embden-MeyerhofParnas pathway
(Homofermentative)
Glucose
Lactate
Fructose
Trehalose
&
disaccharide
acetate
Aspartate
Pyruvate
Polyols
Monosaccharides
Mouthfeel & body
Fatty acids
contribution
& Lipids
D-lactate
Glucose Fructose
Buttery, nutty
aroma/flavour
Phenols
(gallic acid & anthocyananins)
Hexoses
Lipids
lipase
Volatile fatty acids
Fruity aroma
Oak products
Hydrolase
?
furfural
Phenolic acids
p-coumaric acid Biogenic amine
production
4-ethyl guaiacol
histamine &
4-ethyl phenol
tyramine
Spicy, clove
sweaty, bandaid
Copper ions
Inhibitory to growth
Eveline Bartowski, AWRI, 2004
Key Interrelationships of Factors
Affecting ML Fermentation
ALCOHOL CONTENT
TEMPERATURE
CELL
NUMBERS &
HEALTH
TOXIC
FACTORS
STRAIN
SELECTION
NUTRITIONAL
FACTORS
COMPETITIVE
FACTORS
INTERACTION OF
PARAMETERS
bacteria
10x volume of water
20 MINUTES
+ 10x volume of wine
pH > 3.5
After 18 – 24 h
Final
wine
volume
Conclusion
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Proper inoculation rate
Strain selection
Proper Rehydration
Temperature Control
Balanced nutrient (and oxygen) additions
Timing of additions
Thank you!
• For more information on any of these
HUGE topics…
please contact:
– Jessica Just ([email protected])
– Sigrid G-B ([email protected])