wine making and malolactic fermentation

Son hong-seok

color-red, white, rose, yellow wine taste-sweet, dry Alcohol content-fortified,

unfortified(below15%) CO2-sparkling, still meal-appetizer, table, dessert Narrow meaning-grape wine Wide meaning-fruit wine (ex. Apple wine)

Color, sugar, acid, pH-It is important to decide harvest time 1.Sugar D-glucose and L-fructose-1:1 ratio First glucose consumption -most residual sugar fructose %Alcohol(v/v)=0.58X(Brix-2.1)Xdensity Each 1.7%(w/v)=1% alcohol(v/v) 2.Acid Tartaric acid is unique to vine. malic acid is exist in many

fruit. At first 1:1 ratioa but malic acid decrease as ripening(later 3:1)

Total titratable acid(mainly malic, tartaric acid )-3~15g/L Nomally grape pH:2.9~3.8 3.Maturity Brix, TA, pH must be balanced.

Destemming-decrease tannin level and block green flavor

Crushing-juice release 1.White grape After straight pressing (no crushing) sulfite

addition-make a part oxidize and polymerize phenol(It seems to block later browning reaction

2.Red grape Separate free run wine and pressed wine 을 -used

for flavor, body One man use stem-increase tannin level and

complexity …..but?

1.antioxidant-prevent enzymatic oxidation by polyphenolic compound before fermentation and chemical oxidation in age and bottle

2.inhibit microbial spoilage 3.white wine-keep up fruitiness White-30~60, red- 80ppm addition(rotten

grape- more addition 50~100%, because aldehyde(SO2 fixation)level high

Skin contact decide type, character, aging period and quality of wine

Skin contain flavor(cinnamic acid derivatives or flavonols group), pigment(anthocyanin), tannin(anthocyanin derivatives polymeric form or benzoic acid)

High temp, alcohol, SO2, time-mant phenolic compound extraction

Monomeric anthocyanin-extract first color pigment polymeric tannin molecule-extract later

#Carbonic maceration-fermentation without remove stem. You can gain light wine with good color and low tannin.

#Thermovinification-whole cluster is treated by hot air or steam. Because color polymerize and precipitate in bottom, long aged wine has no benefits

1.Acidity problem deficiency-1.blending with other must 2.acid adjustment 3.ion exchange method(K to H) excess-1.blend with low acidity 2.using chemical(CaCO3,K2CO3) 3.ML fermentation 4.cold stabilization 2.Sugar-If sugar lever is low, you can

addite sucrose or grape concentration.

1.alcohol fermentation Yeast use half energy and loss the other half for

heat energy. 2.stuck fermentation-oxizen, nutrient deficiency, yeast problem, low

temperature 3.by-product-glycerol, methanol, higher alcohol, volatile acid,

lactic acid, acetaldehyde, hydrogen sulfide 4.ML fermentation-red wine-good for complexity and increase bouquet.

Inoculate ML stater after several days later alcohol fermentation

glucoseglucose

↓ ↓

Pyruvate ( CHPyruvate ( CH33-C-COH)-C-COH)

Alcohol synthesis processAlcohol synthesis process

Pyruvate decarborylasePyruvate decarborylase

Acetaldehyde (CH3-C-H)Acetaldehyde (CH3-C-H)

EthanolEthanol

Alcohol dehydrogenase (CHAlcohol dehydrogenase (CH33CHCH22-OH)-OH)

COCO22

NADH+HNADH+H++

NADNAD++

OO

OO

Ethanol (CHEthanol (CH33CHCH22OH)OH)

↓ ↓

acetaldehyde (CHacetaldehyde (CH33-COH)-COH)

Alcohol degradation processAlcohol degradation process

Acetaldehyde dehydrogenaseAcetaldehyde dehydrogenase

Acetate (CHAcetate (CH33-COOH)-COOH)

Acetyl CoA (CHAcetyl CoA (CH33-COS-CoA)-COS-CoA)

Acetyl CoA synthetaseAcetyl CoA synthetaseCoASH+ATPCoASH+ATP

AMP+ppiAMP+ppi

Alcohol dehydrogenase

NADH+HNADH+H++

NADH+HNADH+H++

NADNAD++

NADNAD++

Acetic acidAcetic acid

(acetobater)(acetobater)

EthanolEthanol

(body)(body)

Concept of fermentationConcept of fermentation

Glucose

glycolysis

pyruvic acid

T C A T C A

fermentation2EtOH+ 2CO2 + 2ATP

6CO2 + 6H2O + 36ATP

6CO2 + 6H2O C6H12O6(glucose)+ 6O2

sun Energy

Green plantgluconeogenesis

Alcohol synthesis

O2 (respiration)

Stopping fermentation 1. Deep cooling- below 10C 2. Natural stopping-later havested must(nutrition

deficiency and high sucrose level do act inhibition factor. As alcohol content high, fermentation stop of itself)

3. Alcohol fortification-above 18% Method of to prevent Refermentation 1. Yeast inhibitor-200~250ppm 의 potassium-

sorbate 2. Pasteurization-80C, short seconds 3. Sterile filtration-0.45micron filter, yeast

mechanical removing

two mechanism 1. electrical or cohesion force-absorb particle

to filter texture(fiber pad) 2. size control of pores-membrane filter 3 type of filtration 1.Pad filter 2.Membrane filter 3.Mechnical separation Objection of blending 1. supplement demerit of wine 의 2. enhancing complexity-increase quality

objection 1.help precipitation of Suspended meterial 2.decrease bad color and smell 3.prevent later cloudiness and for stabilization Principle 1.charge cancellation 2.absorbtion of the suspended particle Fining agent -Bentonite, Activated carbon, Gelatin, Egg

white, PVPP

Malolactic fermentation(MLF)?

Study on the malolactic fermentation

Crushing

Fermentation

Pressing

Aging

Filtering

Bottling

Harvest

Malolactic fermentation

-2nd fermentation-Malic acid → Lactic acid-Deacidificaton-Make wine soft-Formation of bouquet

Malolactic Fermentation

Study on the malolactic fermentation

using D,L-isomer each 50%

ML bacteria trasfer citric acid to acetic acid

Using ML bacteria upper 20C

Decrease total titratable acidity(di-acid mono-acid)

Good for red wine but white wine ??

Inoculate ML stater after several days later stating alcohol fermentation

ML-fermentation inhibition

Study on the malolactic fermentation

1.Early racking

2.Early fining and filtering

4.The pH

3.Sulfur dioxide

5.Keeping and storing the wine in cellar

6.Membrane filtering

7.Chemical inhibition

Chemistry of MLF

HOOC-CH2-CHOH-COOH CH3-CHCH-COOH + CO2

L-malic acid L-lactic acid

Lactic acid Bacteria

(Lactobacillus, Pediococcus, Leuconostoc)

NAD+, Mn2+

Study on the malolactic fermentation

Main product

Sugar, citric acid, ect acetic acid, diacetyl, acetoin, 2,3-butandiol, ect

By product

Reduction of acidity : acidity 1-3g/L ↓ , pH 0.1-0.3 ↑

Flavor change : diacetyl, acetoin, 2,3-butandiol, volatile ester

Microbial stability

Result of MLF

pH Oxygen

Phenolics

NutrientSO2

Factors affecting MLF

FactorsAffecting

MLF

Temp.

MLFMLF

Warmer condition

Around 25C

anaerobes bacteria (microaeraophilic bacteria)

Sensitive to low pH

Higher then pH 3.4

Very effective inhibitor

Less than 25ppm

Need vital nutrient

(vitamin, glucose ect.)

• Phenolic compounds

• Anthocyanin

Chemistry of MLF

Study on the malolactic fermentation

Phenolic compounds are very important factor of wine

- directly related to wine color and quality (esp. red wine)

- contribute to the organolectic characteristics of wine

- act as antioxidant

The chemical change of phenolic compounds during aging is very sensitive to many factors

MLF decrease the color intensity and hue

Color can be stabilized, particularly in barrels : tannin-anthocyanin condensation

MLF increase polymerization of tannin and anthocyanin

Oxidative condensation during wine aging

Wine color / Phenolic compounds / Malolactic fermentation

HO2C

HO

O

OH

OH

C

O

C C

H H

OH

OH

O

OH

OH

HO

OH

OH

OH

CH=CH2-COOH

OH

LC chromatographic profile of the phenolic compounds of wine(V. vinifera)

Study on the malolactic fermentation

Gallic acid

Quercetin derivative

tryptophol

Procyanidin trimer

quercetin

Myricetin

Tyrosol

- Gallic acid

- falvanol

- catechin, epicatechin

- miricetin

- tyrosol, trytopol

Phenolic compounds of wine

Influence of anthocyanin on MLF

Study on the malolactic fermentation

Fig. Influence of free anthocyanin on the growth of L. oenos(carr medium)

() control; () anthocyanin

Fig. Influence of free anthocyanin and malvidin- 3-mG on the range of MLF

() control; () antocyanin; () malvidin-3-mG

• Free anthocyanin showed a very limited effect on the growth of L. oenos during the early growth phase

• Also free anthocyanin had a effect on malolactic fermation

Evolution of phenolic compounds during MLF

Study on the malolactic fermentation

Table Concentration of phenolic compounds(mg1-1) in the wine before and after MLF

• Hydrocynamic derivatives dropped sharply until they disappeared completely

-> increase the free form

• Hydrolysis reaction affecting hydrocinamic derivatives could be take place during MLF

• trans-caffeic acid and trans-p-coumaric acid come from the other hydroxycinamic derivatives or

anthocyanin by lactic acid bacteria

My first wine-Coreju-a