Presentation is loading. Please wait.

Presentation is loading. Please wait.

Monitoring Acids and pH in Winemaking Mike Miller The Reluctant Chemist.

Similar presentations

Presentation on theme: "Monitoring Acids and pH in Winemaking Mike Miller The Reluctant Chemist."— Presentation transcript:

1 Monitoring Acids and pH in Winemaking Mike Miller The Reluctant Chemist



4 TA Conversions % TA to g/L: multiply by % TA = 7 g/L meq/L to g/L: divide by meq/L = 7.5 g/L g H 2 SO 4 /L to g tartaric/L: multiply by g H 2 SO 4 /L = 7.5 g tartaric acid/L

5 Why are pH and TA important? pH ~ sourness pH and TA ~ astringency High pH = less red, more brown High pH = reduced capacity to mature High pH = more ionized components, more oxidation High pH = poor bentonite fining; greater protein instability High pH = greater susceptibility of bacterial growth pH + TA balance sugar + alcohol + glycerol

6 The major winemaking acids Tartaric Malic Citric L-Lactic Succinic

7 What are the optimum levels? pH: 3.3 – – 3.4 TA: 6 – 8 g/L 7 – 9 g/L

8 How can I increase TA levels? Add tartaric acid Add DL-malic acid Add L-malic acid Add L-lactic acid Add citric acid Add fumaric acid Add sorbic acid

9 How can I decrease acidity levels? Maloalcoholic fermentation Deacidify with calcium carbonate Deacidify with potassium bicarbonate Treat with Acidex (takes two steps) Conduct MLF Blend Stabilize Ameliorate

10 How do I adjust pH? Ion exchange Sulfuric acid?

11 What about those acids I dont want? D-Lactic acid Acetic acid

12 And that other acid? Sulfurous acid, a.k.a. SO 2

13 SO 2 Chemistry SO 2 + H 2 O = HSO H +


15 How can I best control pH, Acids, and Acidity? Monitor

16 Wine and winemaking problems Name of ProblemFlawFaultCaused by faulty Winemaking Presence of reduced sulfur compounds (e.g., H2S)20%80%20% Presence of acetaldehyde5%95%100% MLF in bottled wine40%60%80% Yeast Fermentation in bottled wine50% 100% Presence of ethyl acetate5%95%10% Inadequate settling of white juice80%20%100% Presence of tyrene (T.C.A. = corkiness)20%80%0% Presence of 2,3-ethoxy-3,4-hexadiene (geranium)5%95%90% Presence of volatile acidity – acetic acid80%20%80% Presence of diacetyl90%10%50% Brettanomyces contamination80%20%0% Additive overuse (SO 2, sorbate,etc.)90%10%100%

17 When should I monitor? Harvest monitoring Upon receipt After primary fermentation After malolactic fermentation After any process Periodically

Download ppt "Monitoring Acids and pH in Winemaking Mike Miller The Reluctant Chemist."

Similar presentations

Ads by Google