Harvest Series 2017: Yeast Nutrition

Transcription

1 Harvest Series 2017: Yeast Nutrition Jasha Karasek Winemaking specialist Enartis USA

2 WEBINAR INFO 40 Minute presentation + 20 minute Q&A Save Qs until end of presentation Use chat box for audio/connection issues Poll questions Recording in progress Exclusive coupon code at end of webinar Please fill out our survey in follow-up !

3 Overview Importance in winemaking Yeast nutrition requirements Nitrogen uptake Nutrient application timing Nutrients for aromas Preventing sluggish ferments Juice nutrient status

4 Why Do We Care? Sluggish/Stuck fermentation H 2 S / Sulfide formation Flavor/aroma development Time constraints

5 Yeast Nutritional Requirements Biocheminal function Enological effect Addition NITROGEN Protein synthesis - Stimulate yeast multiplication - Prevent H 2 S production - Stimulate aromas production inoculation 1/3 fermentation STEROLS AND FATTY ACIDS (Survival factors) Components of yeast cell membrane - Maintain yeast membrane activity - Increase yeast resistance - Reduce off flavors production 1/3 fermentation THIAMINE Co-enzyme - Stimulate yeast growth Inoculation Mg-Zn Co-enzyme - Maintain yeast metabolism active Inoculation

6 Yeast Nitrogen inorganic Nitrogen organic CHALLENGES Amino acid uptake in presence of ethanol is very limited High NH 4 + limits Amino acid uptake in early fermentation

7 Nutrient addition timing Complex nutrients/dap Added at 1/3 Brix Drop Cell # Organic Nutrients Added in Innoculation Time Brix

8 Organic Nutrients AA content AA quality Thiamine Other Micronutrients High Building cell mass Preserves varietal expression Very High Aromatic precursors Strong fermentation Sterols/ Fatty Acids.15% High Moderate.15% High Moderate

9 yeast (cell/ml) Thiamine Co-Enzyme: Allows pyruvic acid to be converted to Ethanol in fermentation 2,00E+08 1,80E+08 1,60E+08 1,40E+08 1,20E+08 1,00E+08 8,00E+07 6,00E+07 4,00E+07 2,00E+07 0,00E+00 INFLUENCE ON YEAST GROWTH With thiamine Without thiamine Time (hours) WARNING! THIAMINE CAN BE INACTIVATED BY SO 2 : ADD 2-3 HOURS AFTER SULFITING

10 Boosting Fermentation Aromatics Main factors influencing wine aromas: Varietal precursors Yeast strain Fermentation kinetics Amino acid content of juice

11 HOW IT WORKS NH 3 Acetyl- CoA CoA AA - phenylalanine CO Higher Alcohol 2-phenylethanol Floral Alcohol Acetyl Transferase 2-phenylethyl acetate Rose/Honey ESTERS CONCENTRATION (mg/l) AROMA 2-phenylethyl acetate Rose, honey Isoamyl acetate Banana, pear Isobutyl acetate ,8 Banana Hexyl acetate Ripe apple Ethyl Butanoate Flower, fruit Ethyl caproate Traces-3.4 Apple

12 Nutriferm Arom Plus vs. DAP Aroma Threshold (mg/l) DAP (mg/l) NUTRIFERM AROM PLUS (mg/l) Ethyl butyrate APPLE APPLE PEEL Ethyl hexanoate BERRIES PINEAPPLE Ethyl octanoate FRUIT Ethyl decanoate GRAPE Isoamyl alcohol 2-phenylethanol WHISKY BANANA ROSE LILIAC

13 Yeast selection for Arom plus For Nutriferm Arom plus, use high ester producing yeast

14 Nutrient addition timing Complex nutrients/dap Added at 1/3 Brix Drop Cell # Organic Nutrients Added in Innoculation Time Brix

15 glucose transport speed (µmol xyl/h/g) Mid Fermentation DAP addition EFFECT OF NITROGEN ADDITION ON SUGAR TRANSPORT SPEED AT 1/3 FERMENTATION (Salmon, 1989) 2,5 2 NITROGEN CONTROL 1,5 1 NITROGEN AT HALF A.F. 0, ,1 0,2 0,3 0,4 0,5 0,6 0,7 Fermentation progression

16 Nutriferm Gradual Release DAP+ (90%), Gallic tannin, and Untoasted oak tannin Slowly releases NH 4 + Permeability dependent on [EtOH] Complete dissolution of product Eliminate multiple adds Maximize AA uptake Deliver NH 4+ slowly over course of fermentation limit H 2 S production

17 Released product % Nutriferm Gradual Release days

18 Preventing Stuck/Sluggish Fermentations Sterols Challenges: EtOH EtOH EtOH Long chain Fatty acids EtOH Yeast require fluid membrane cellular function Yeast require sterols to maintain membrane fluidity Yeast produce sterols with the aid of oxygen Low oxygen in fermentation environment inhibits sterol production EtOH

19 Complex Nutrients Yeast cell walls rich in: Unsaturated long-chain fatty acids Sterols Prevents Stuck/sluggish ferments Added to must at 1/2 sugar depletion with good YAN levels Enriched Yeast hulls, DAP, cellulose Provides sterols, long chain fatty acids Vitamins Essential micronutrients Detoxifies must Prevents stuck/sluggish fermentations Added to must at 1/3 sugar depletion

20 Yeast nutrition strategies or Juice 1/3 Sugar depletion 1/2 Sugar depletion Nutriferm gradual release

21 Measuring Yeast Nutrient Status YAN Yeast Assimilable Nitrogen by Enzymatics - Nitrogen from amino acids - Nitrogen from NH 4 + Brix level important: 1 Brix req. approx. 10 mg/l YAN Total YAN required Dependent on Yeast strain, nutrient quality