« The
role of yeast in winemaking is not
limited
to alcoholic fermentation »
Without yeast
… it’s just juice!
>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
Organic nitrogen
vs
Inorganic nitrogen
1,4
Chardonnay 220 g/L sucre, desaerated
EC 1118 (20g/hl)
dCO2/dt (g/l.h)
1,2
20 mgN/l
Ammonium (DAP)
1
0,8
Amino acid : more efficient
0,6
5 mgN/l
Amino acids
0,4
than ammonium
0,2
8°
0
0
50
time (h)
100
40°
150
200
Effect on Fermentation Kinetics of GO-FERM® Micronutrient Addition During
Yeast Rehydration
A. Julien, J. Sablayrolles - INRA Montpellier 2001
0,9
0,8
Uvaferm CEG inoculated at 25g/hl into
MS 70 medium – CO2 evolution at 24oC
Greater degree of slope indicates
Stronger fermentation finish
dCO2/dt (g/l.h)
0,7
0,6
0,5
0,4
Control – sluggish fermentation
0,3
0,2
30g/hl GO-FERM®
added at rehydration
0,1
19° slope
43°slope
0
0
50
100
150
200
250
Time (h)
300
350
400
450
Protection / Nutrition:
differences of impact on yeast
• Protection: in rehydration step
( effect on yeast membrane)
– Improve alcohol resistance
– Improve viability at the end of fermentation
– Less stress for the yeast = low VA
• Nutrition: In Beginning & Mid AF
( effect on cellular growth and fermentative
activity)
– Improve yeast multiplication
– Improve sugar consumption
– Improve aroma expression
ORIGIN OF WINE POLYSACCHARIDES
Grape polysaccharides
Mould polysaccharides
(Botrytis cinerea)
Yeast Polysaccharides
THE YEAST CELL WALL
(Schreuder et al. 1996)
Production of polysaccarides during alcoholic
fermentation (S. Escot, 1999)
Day 0
Day 4
day 7
Polysaccharide production after fermentation with
27 different SACCHAROMYCES CEREVISIAE strains
(HPLC)
Polisaccaridi (mg/l)
160
140
120
100
80
60
40
20
0
Ceppi
Yeast and color
Sponge effect : beginning of the story
Same must of
Grenache,
microvinifications with
3 different strains of
yeast (Institut
Rhodanien)
Lees don’t have the same color
Yeast and color
Strain specificity of the mannoproteins release
20
15
RC212
10
BM45
5
Au FA
to
ly
si
s
d
o
24
ex
p
en
Time (hours)
p,
8
4
0
0
Polys./100g of biomass
(S. Escot, 2000)
Polysaccharides released during the AF in function of the yeast strain
Yeast and color
70
60
50
40
30
20
10
0
10
0
m
C
20 g R ont
r
0
C
21 ol
m
g
2
10 RC FA
0
21
m
2
F
20 g B
M A
0
10 mg 45
0
m BM FA
20 g R 45
0
C
21 FA
m
g
2
10 RC au
0
21 t
m
2
a
20 g B
M ut
0
45
m
g
BM au
45 t
au
t
I of gelatin (%)
Qualitative effect of mannoproteins : decrease of astringency
Variation of gelatin index of a young wine of Pinot noir not filtered after addition
of distinct mannoproteins (S. Escot et al., 2000)
Yeast and color
A practical case : Madiran
(A. Fuster and S. Escot, 2000)
RC212
855
BM45
875
PVPP index
38
45
Ionization index
54
75
Tanins (g/L)
5.8
5.6
Ethanol index
7.7
9.2
Tannic power
47.5
39.2
Color Intensity
31.9
35.5
Anthocyans
(mg/L)
Grape variety : tannat 2000, measured after 3 months of ageing on lees
AWRI results (Simon et al., 2002)
y
Langhorne Creek
Polymeric
pigmented
tanino
Figure 3 : polyphenolic characterístics of
wines obtained from grapes from different
zones and with different yeast strains
-m-3-g coumaric
m-3-acetil-g
Clare Valley
z
m-3-g
x
Adelaide Hills
Gallic acid
Although the yeast has an effect on the final quality of the
wine, the zone of production of the grapes is also important =
therefore selected yeast are not a tool of standardization of
the wines !
Life of yeast in winemaking
Yeast implantation
in the must
-Mouthfeel increase
-Nutrition
-Antioxydant properties
-Flavour
-Wine stability (p&t)
-Mannoproteins
-Proteins
-Peptides
-Nucleotides
Yeast multiplication
Low release of yeast components
Fermentation
Yeast autolysis
High release of yeast components
Aging on lees
Yeast is an incredible source of interesting
elements !!
 Amino-acids and peptides
 aromas precursors
 yeast bacteria nutrients
 antioxydants (glutathion, a tripeptide)
 Nucleic acids
 organoleptic properties
 Volatile aromatic compounds
 Polysaccharides (mannoproteins & glucans)
 colloidal interactions
 mouthfeel improvement
 Micronutriments (sterols; vitamins)
 yeast protection
 yeast nutrition
 bacteria nutrition
Origin and organoleptic properties of yeast compounds released
during aging
Flavour agents (nucleotides, nucleosides)
Mouthfeel, roundness (Polysacharides
& mannoproteins)
From Charpentier & Feuillat 2003
Free aromas
Flavour, bitterness (amino acids,
peptides)
Inactivated yeasts can be used for :
 To obtain steady, complete and secure fermentation :
 Protection of the active dry yeast during its rehydration
 Nutrition of the yeast during alcoholic fermentation
 Nutrition of bacteria during malolactic fermentation
 To increase quality of the wine :
 Aromas and color protection
 Mouthfeel increase
 Astringency, bitterness decrease
Yeast
Dead or alive!!
*The next generation*
Liberation kinetic :
Accelerated by temperature
28 °C
Mannoprotéines
relarguées (mg/L)
160
140
15 °C during 6 months,
then 28 °C
120
100
80
5 °C
60
40
20
0
0
2
4
6
8
10
Temps (mois)
12
14
Yeast Autolysis-a reminder!
Controlled process
Enzymatic degradation of cell
Wines impose particular (unfavorable) conditions
- Low pH
- Low temperature
Optimal conditions for autolysis:
pH 5, 113 ˚F (45˚C)
Compensate with time and stirring
Faster in white wines
Consider the level of poly-phenolics
• Specific Inactivated Enological Yeast
• Enological yeast treated to suppress their fermentation
capacity.
• Inactivated by different methods then purified
• Enzymatic, Physico-chemical
• Arrest growth at the end of the exponential
phase
Specific Inactive Yeast.
• Yeast cells grown on respiration: no sulfur
compounds risks
• Inactivated sulfite reductase
• Ability to bring longevity
• Ability to adsorb different dangerous molecules, like
light sulfur compounds
• Ability to combine and partially eliminate aggressive
tannins
Effect of Specific Inactivated Yeast
With the correct dose:
– Increase fruity aromas
– Reduce vegetal notes
– Increase volume perception
– Increase tannic intensity (in mid-palate)
– Reduce bitterness
– Stabilize the colloidal matrix
– Increase Longevity
• Positive synergy with FermaidK
• With starved yeast cells, increase the potential for Volatile Sulfur
Compounds (VSC’s)
• VSC’s enhance the aggressiveness of a wine





Lees aging
• End of alcoholic fermentation
• Loss of cellular viability
E
E
E
E
E
E
E
E
E
E
E enzymes
E
: biopolymers
 Polysaccharides: Mannoproteins
 Sulfur compounds
 Fatty acids
Heavy lees
• Heavy lees are compounds which
settle in a wine without pectins in
less than 24 hours after a
movement
• Size of heavy lees : from a
hundred microns to some
millimeters.
Light lees
• Light lees which do not settle 24
hours after a movement of wine
• Movements are : racking off,
pumping, stirring, ...
• Size of light lees : from a micron
to some ten microns.
Liberation of mannoproteins depends on:
 Conditions of fermentation:
Composition of the juice/wine matrix
Temperture
Agitation
Lees contact time
Yeast strain
ACTION HYPOTHESIS OF MANNOPROTEINS
ON TANNINS
(Saucier et al, 1996) :
Van der Walls
interactions
flavanol
molecules
Precipitation
colloidal particles in
flavanols
Protéine
interactions
Hydrophobe
Concentration in flavanol
(pH, temperature)
Protéine
To summarize :
Yeast can act on the polyphenolics content of the wine :
-through the sponge effect
-via some of its polysaccharides released during the fermentation
-with the action of some b-glycosidases
but the population of yeast is variable and not reproducible
This effect don’t mask the terroir influence
Alcoholic Fermentation.
Grape quality.
- Wine goal: Roundness, volume
- Low maturity grapes (green, high yield,
unbalanced tannins)
- Varieties with colour stability problems
- In whites, colour and aromas protection
- Wine goal: Structure
- High maturity grapes
- Long maceration
- Varieties with low acidity, high alcohol
degree...
- In whites, colour and aromas protection
BoosterRouge®
BoosterBl anc®
WHEN & WHY
IN FERMENTATION
BoosterRouge®
COLOR STABILITY
ROUNDNESS & SMOOTHER TANNINS
REDUCTION OF HERBACEOUS
FRUITINESS
PREVENT SULFUR OFF FLAVORS
WHEN & WHY
IN FERMENTATION
BoosterBlanc®
MANTAIN THE AROMATIC POTENTIAL
MOUTHFEEL
PREVENT SULFUR OFF FLAVORS
REDUCTION OF ACID SENSATION
WHEN & WHY
POST FERMENTATION
BoosterRouge®
BoosterBlanc®
ROUNDNESS & MOUTHFEEL
“RE-FRESHING” THE AROMATIC POTENTIAL
CURE LIGHT HERBACEOUS & SULFUR OFF
FLAVOURS
INTEGRATION WITH WOOD!
REDUCTION OF ALCOHOL SENSATION
BoosterBlanc®
After Alcoholic Fermentation .
 OPTIRED.
Optired has a more significant contribution
in mouthfeel increase and decrease of some negative notes
(green notes, dry taninns…).
 BOOSTER ROUGE.
High-end red wines from ripe and concentrated grapes: to
increase the freshness and the tannic intensity in the midpalate.
 NOBLESSE.
More intense perception of the fruit, overall structure, less
perception of woody aromas (integration of alcohol, acidity and
oak). Without Sulphite reductase potential.
After Alcoholic Fermentation .
 Factors involved in the treatments.
Temperature.
Stirring (Battonage).
 Contact time of the SIY:
OptiRED < Booster Rouge < Noblesse
Oh! And don’t forget …
• Is a sulphite addition necessary?
1) Adapt to pH
2) Adjust to bacteria load in wine
– When to sulphite is very important:
• After racking off lees in reds
• Within 24 hours in whites and rosé
• Maintain sulphite levels during battonage
• Critical to avoid oxidation and maintain freshness of
the wine= add smaller, incremental additions of
sulphite
GRAPE QUALITY AND WINE GOAL (LOW MATURITY GRAPES)
Aromatic Profile:
GREEN
2
1
0
1
1
0
1
JAMMY
2
Mouthfeel:
2
STRUCTURE
ROUNDNESS 2
Longevity:
2
HIGH CAPACITY
1
0
1
LOW CAPACITY
2
SAM HARROP MW / CARLOS
GRAPE QUALITY AND WINE GOAL (HIGH MATURITY GRAPES)
Aromatic profile:
FRESH FRUIT
2
1
0
1
1
0
1
JAMMY
2
BoosterRouge®
Mouthfeel:
2
STRUCTURE
ROUNDNESS 2
BoosterRouge®
Longevity:
2
HIGH CAPACITY
1
0
1
LOW CAPACITY
BoosterRouge®
SAM HARROP MW / CARLOS
2
GRAPE QUALITY AND WINE GOAL (BALANCE GRAPES)
Aromatic profile:
FRESH FRUIT
2
1
0
1
1
0
1
JAMMY
2
Mouthfeel:
2
STRUCTURE
ROUNDNESS 2
Longevity:
2
HIGH CAPACITY
1
0
1
LOW CAPACITY
SAM HARROP MW / CARLOS
2
R&D - ICV results
Sauvignon blanc - R&D ICV - 2005
4
Control
BoosterBlanc® 30 g / hL beginning of AF + Fermaid®
3
2
1
0
Chemical
Vegetal
Trop. Fruits
White fruits
Jam
CONTEXT
 Many wines have « reduction » and S off-flavors ‘issues’
 Large quantities of wine lose value because of S off-flavors
 Traditionnal copper treatment is not always efficient and negatively
impacts wine quality
CONCLUSION
What grapes? Quality? Wine goal?
Opportunities: Synergies with other practices and
oenological products: Microoxygenation, use of tannins….
MLF friendly products.
 After Alcoholic fermentation, these specific yeast
derived products can contribute to the quality of wine and
therefore the commercial success.
Taste, agitations? timing of treatments?
Thank you for your attention!
[email protected]