High Alcohol Wines: How to Manage Primary and Secondary Fermentation

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High Alcohol Wines How to Manage Primary and
Secondary Fermentation

• Presented by
• Jessica Just of Scott Laboratories
• and
• Sigrid Gertsen-Briand of Lallemand

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Winemaking Goals in a High Sugar Ferment

• 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

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Yeast
Glucose
CO2
Ethanol
Internal pH is 5-6
Esters
H
H
Glycerol
Organic Acids
Higher Alcohols
Biomass ( 2 glucose)
H
H
External pH is 3-4
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Normal Fermentation Curve
Higher yeast inoculation rate lowers dilution of
the initial yeast cells survival factors
gt100-150 million CFU/mL
Population
4-8 million CFU/mL
2-4 million CFU/mL
2-4 million CFU/mL
Brix
Time
Survival factors are important to ensuring the
proper working of the cellular membrane
poly-unsaturated fatty acids and sterols
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Key Interrelationships of Factors Affecting
Fermentation
SUGAR CONTENT
STRAIN SELECTION
TEMPERATURE
MAXIMUM FERMENTATION MANAGEMENT
CELLNUMBERS HEALTH
NUTRIENTS and OXYGEN
TOXIC FACTORS
COMPETITIVEFACTORS
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Temperature Control in Red Must
Max. Temperature

• 20 Brix
• 21 Brix
• 22 Brix
• 23 Brix
• gt24 Brix

• 95F
• 90F
• 85F
• 80F
• 76F

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What to Know Before Restarting a Stuck Alcoholic
Fermentation

• Total residual sugar
• GlucoseFructose ratio
• What caused the stuck fermentation
• Which yeast strain was used for the initial
  fermentation
• Temperature control

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Dealing with a Stuck Alcoholic Fermentation

• 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?

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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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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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Pentoses
Hexoses
phosphoketoslase pathway (Heterofermentative)
Embden-Meyerhof-Parnas pathway (Homofermentative)
pentose phosphate pathway
Citrate
Glucose
Lactate acetate
Fructose
BACTERIA
Acetate
WINE
Trehalose
disaccharide
Oxaloacetate
Aspartate
Pyruvate
Polyols
L-Malate
Mannoprotein
Monosaccharides
Fatty acids Lipids
Pyruvate
Mouthfeel body contribution
L-lactate
Diacetyl
D-lactate
More efficient malic acid degradation
Glucose
Fructose
0.1-0.2 units increase in pH (palate)
Buttery, nutty aroma/flavour
Glycerol erythritol
Esters synthesis hydrolysis
Mannitol
Phenols (gallic acid anthocyananins)
Polysaccharides
Ethylesters esterase ethyl lactate, ethyl
acetate, ethyl hexanoate, ethyl octanate
Mouthfeel contribution
b(1-gt3) glucanse
Lipids
Sucrose, trehalose phenolic glucosides
lipase
Growth stimulation of MLF
Volatile fatty acids
Protein
Colour reduction
Glycoside (flavour)
Sugar-anthocyanin
Fruity aroma
protease
Oak products
b-glucosidase
Hydrolase ?
Peptides
Sugar flavour-aglycon
glycosidase (anthocyanase)
Bitterness ? flavour
furfural
Increase in aroma Cell growth
Phenolic acids
Sugar anthocyanidin
p-coumaric acid
Adsorption by cells Cell growth
Biogenic amine production histamine tyramine
Ethanol
Citrulline, urea
4-ethyl guaiacol 4-ethyl phenol
SO2-acetaldehyde
Spicy, clove sweaty, bandaid
Mousy compounds
Ethyl lactate
Ethyl carbamate
Bruised apple (green, vegetative)
Copper ions
Acetate ethanol free SO2
carcinogen
Off-flavour
Inhibitory to growth
Eveline Bartowski, AWRI, 2004
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Key Interrelationships of Factors Affecting ML
Fermentation
ALCOHOL CONTENT
STRAIN SELECTION
TEMPERATURE
CELLNUMBERS HEALTH
NUTRITIONALFACTORS
TOXIC FACTORS
COMPETITIVEFACTORS
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INTERACTION OF PARAMETERS
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bacteria
10x volume of water
20 MINUTES
10x volume of wine pH gt 3.5
After 18 24 h
Final wine volume
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Conclusion

• Proper inoculation rate
• Strain selection
• Proper Rehydration
• Temperature Control
• Balanced nutrient (and oxygen) additions
• Timing of additions

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Thank you!

• For more information on any of these HUGE topics
  
• please contact
• Jessica Just (jessicaj_at_scottlab.com)
• Sigrid G-B (sigrid_at_lallemand.com)