Christian Butzke Enology Professor.

Christian Butzke Enology Professor butzke@purdue.edu www.indyinternational.org www.indianaquality.org

SO 2 & Sorbate Management Oxygen Management Skin Contact Time Residual Nutrients Temperature, ph & Browning Bulk & Bottle Storage

SO 2 Deficiencies Example: 26 Traminettes Deficient! Fine!

SO 2 Management Free SO - 150 Free SO 2 required SO 2 molecular - 75 (mg/l) ph 2.9 3.2 3.5 3.8 4.1-0 ph

ph and Required SO 2 Free SO 2 = 0.85 (1 + 10 ph - 1.83 ) required Or see chart @ www.indianaquality.org/freeso2(ph)pro.pdf

Free SO 2 Decline Percentage of decline in SO 2 for 3 different temperatures

Yeast growth inhibitor: Legal limit: Sensory threshold: Some yeasts are resistant! NO effect against bacteria Sorbic Acid Basics Likely effective against Brett 200 mg/l 300 mg/l 135 mg/l Added as potassium salt (Sorbate @ 268 mg/l)) => Watch cold stability!

Geranium Off-Odor Cause Sorbic acid + Malolactic bacteria Prevention Avoid sorbate as preservative Use sorbate only with proper SO 2 Add no earlier than day before bottling Always bubble test/sterile filter NO removal option from wine

Sorbate Management Sorbate sensitivity: Malolactic bacteria? Saccharomyces? NO! YES! Brettanomyces? MAYBE?

Sorbate Mixing I mixed up potassium sorbate and citric acid together to make a sorbate addition and an acid adjustment prior to bottling. An amorphous white precipitate has formed and is floating on top of the mixture. What is it and what should I do about it? Winemaking Problems Solved

Sorbate Mixing

SO 2 & Sorbate Management Oxygen Management Skin Contact Time Residual Nutrients Temperature, ph & Browning Bulk & Bottle Storage

Joanna Simon: Discovering Wine Presumed White Wine Aging Average white wine

Oxygen Management Vernon L. Singleton: Principles and Practices of Winemaking

Oxygen Pickup at Bottling

Oxygen Basics Air-O 2 solubility (68 F): 8 mg/l Air-O 2 uptake at bottling 0.17-8 mg/l Uptake per topping: 5 mg/l Uptake per racking: 20 mg/l Uptake via cork: 0.1-100 mg/l Young white wine: Total O 2 uptake capacity: Optimum O 2 uptake: Young red wine: Total O 2 uptake capacity: Optimum O 2 uptake: <100 mg/l 0 mg/l 4,000+ mg/l 60-130 mg/l

Oxygen Pickup at Bottling [mg O 2 /L] Added Added Added at the filler via headspace Total O 2 Gravity flow filler only 6.60 1.40 8.00 Removed Removed Removed at the filler from headspace Total O 2 1. Vacuum pulled at filler 6.00-6.00 2. Bottle sparged with N 2 0.51 0.02 0.53 3. Vacuum pulled at corker - 0.15 0.15 4. Headspace sparged with N 2-1.15 1.15 #1- #4 implemented 6.51 1.32 7.83 = 98%

Oxygen Pickup after Bottling Uptake via cork: 0.1-100 mg/l

Oxygen Pickup after Bottling

SO 2 Loss at/after Bottling O 2 uptake at bottling: 0.17-8 mg/l 8 mg O 2 + 32 mg SO 2 => Sulfate = Free SO 2 Loss + additional losses during filtration etc Add 10 40 mg/l EXTRA SO 2 before bottling

ph and Required SO 2 Free SO 2 = 0.85 (1 + 10 ph - 1.83 ) required Or see chart @ www.indianaquality.org/freeso2(ph)pro.pdf

SO 2 & Sorbate Management Oxygen Management Skin Contact Time Residual Nutrients Temperature, ph & Browning Bulk & Bottle Storage

Skin Contact Time

Terpene Degradation

... our Traminette had skin contact for 24 hours... When considering skin extraction, the contact time is as important as the temperature of the incoming fruit. Contact time for t 1 = 24 hours at 39 F is roughly equivalent to t 2 = 7 hours at T = 59 F Assumed terpene/tannin extraction kinetics: t 2 = t 1 *1/(3 (T-39)*0.056 )

SO 2 Inhibition of Browning Enzymes Polyphenol oxidases Tyrosinase (from grape)? Laccase (from Botrytis)? YES! NO! Option: HTST juice pasteurization

Fermentation Aroma Esters Caprate C 10 Laurate C 12 Pelargonate C 9 Caprylate C 8 Myristate C 14 Expect hydrolysis in 6 weeks to 6 months!

Treatment ISSUES Pre-mature aging? => No aging potential Enzyme vs. natural acid hydrolysis? => Release of non-varietal aromas Removal of stable anthocyanin-glucoside? Additional bentonite fining needed!

EVC EVC EVC EVC EVC EVC EVC EVC EVC EVC EVC EVC EVC EVC EVC EVC EVC EVC EVC EVC

SO 2 & Sorbate Management Oxygen Management Skin Contact Time Residual Nutrients Temperature, ph & Browning Bulk & Bottle Storage

Wine Nutrient Status Do you know how much you ve got? Residual sugars Nitrogen Phosphate Potassium Vitamins Sterols Other growth factors

Hybrid Nutrient Status By Grape Varietal (Primary Amino Nitrogen by NOPA) 250 mg YAN/L 250 mg YAN/L

Haze Formation S.c. may grow if the recommended doses of sorbate and SO 2 are not met. Or if sterile filtration prior to bottling was compromised (use bubble test!). Even 100 mg/l residual pentoses can lead to a visible Brett haze. Visible haze due to S.c. must be expected above 1,000 mg/l R.S. Re-fermentation Rules Yeast Residual Sugar Recognition threshold for sweetness is about 5 g/l (0.5%) 1 to 4 g/l can smoothen a wine without making it taste off-dry. Microbial Stability Sensory perception of dryness is different from microbial stability Wine is dry when its combined fermentable sugars are below 1 g/l (0.1%). Considering all reducing sugars, incl.pentoses, 2 g/l (0.2%) is dry. Even below 2 g/l, R.S. can serve as a substrate for our spoilage microbes. Gas Production 1,000 mg/l R.S. can produce almost 500 mg/l CO 2 gas. To push corks about 1,400 mg/l at room/bottling temperature are required. Strongly influenced by headspace volume and closure type. A perceivable spritz may be tasted at 800 mg/l CO 2 (from 1.6 g/l R.S.).

Re-fermentation Rules Bacteria Malic Acid Grapes at harvest contain between 0.6 and 6 g/l of malic acid Malolactic bacteria turn malic acid into lactic acid and carbonic acid (CO 2 ) Tartaric acid cannot be metabolized by wine bacteria. Absence of a malic acid spot on a paper chromatogram indicates > 30 mg/l. A barely visible spot about 200 mg/l. In wine which completed MLF, residual malic acid is less than 300 mg/l (0.3 g/l). Gas Production Malic acid is converted into two thirds lactic acid and one third CO 2 300 mg/l residual acid could produce 100 mg/l gas. A perceivable spritz may be tasted at 800 mg/l CO 2 (from 2.4 g/l malic). Haze Formation Visible haze in a white wine due to the growth of Oe. oeni above 300 mg/l.

SO 2, Alcohol & MLF Oenococcus oeni suppression: free SO 2 to 0.85 molecular at 12% EtOH free SO 2 to 0.6 molecular at 14% EtOH

SO 2 & Sorbate Management Oxygen Management Skin Contact Time Residual Nutrients Temperature, ph & Browning Bulk & Bottle Storage

% of 50 F Cellar Life Browning & Temperature

Browning & ph Dr. Vern Singleton Professor of Enology Emeritus UC Davis

SO 2 & Sorbate Management Oxygen Management Skin Contact Time Residual Nutrients Temperature, ph & Browning Bulk & Bottle Storage

www.indianaquality.org

Bottle Storage and Aging Whites better off at 32 to 40 F?

Wine Shipments

Temperaturecontrolled trucks that maintain a steady 55 degrees will be used to ship to FedEx hubs.