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

glucose glucose ↓ Pyruvate ( CH 3 -C-COH) Alcohol synthesis process Pyruvate decarborylase Acetaldehyde (CH3-C-H) Ethanol Alcohol dehydrogenase (CH 3 CH 2 -OH) CO 2 NADH+H + NAD + O O

Ethanol (CH 3 CH 2 OH) Ethanol (CH 3 CH 2 OH) ↓ acetaldehyde (CH 3 -COH) Alcohol degradation process Acetaldehyde dehydrogenase Acetate (CH 3 -COOH) Acetyl CoA (CH 3 -COS-CoA) Acetyl CoA synthetase CoASH+ATP AMP+ppi Alcohol dehydrogenase NADH+H + NAD + Acetic acid (acetobater) (acetobater) Ethanol (body)

Concept of fermentation Glucose glycolysis pyruvic acid T C A fermentation 2EtOH+ 2CO 2 + 2ATP 6CO 2 + 6H 2 O + 36ATP 6CO 2 + 6H 2 O C 6 H 12 O 6 (glucose)+ 6O 2 sun Energy Green plant gluconeogenesis Alcohol synthesis O 2 (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-CH 2 -CHOH-COOH CH 3 -CHCH-COOH + CO 2 L-malic acid L-lactic acid Lactic acid Bacteria (Lactobacillus, Pediococcus, Leuconostoc) NAD +, Mn 2+ 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 ↑  Flavor change : diacetyl, acetoin, 2,3-butandiol, volatile ester  Microbial stability Result of MLF

pH Oxygen Phenolics NutrientSO2 Factors affecting MLF Factors Affecting MLF Temp. MLF MLF 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

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