You are using an old browser that may not function as expected. For a better, safer browsing experience, please upgrade your browser.

Log in Become a Member

Ascorbic acid

Colourless and odourless crystalline acid related to sugars and strongly acid governing, its salts are called ascorbates. The name is derived from the Greek "a" (for "not") and the vitamin C deficiency symptom scurvy (meaning "you don't get scurvy"). Of the four existing forms, only L-ascorbic acid is biologically active, which and also its derivatives are grouped together under the name vitamin C. It is found in many fruits and vegetables. It is present in many fruits and vegetables, for example in bush plum (3,150 mg in 100 g), acerola cherry (1,700), rosehip (1,250), black currant (180), kale (150), broccoli (115) and lemon (53). In plant metabolism, it plays an important role in photosynthesis. It is also present in green grapes, but during ripening and vinification its content decreases to zero.

Industrially, ascorbic acid is produced from glucose. As it is easily oxidised, it is used as a preservative or antioxidant. As an oxidation inhibitor, it is mainly used in the New World. The grapes are already sprayed with it after harvesting. It may be added to the wine up to a maximum of 150 mg/l. This is often done together with sulphur dioxide. This is often done together with sulphur dioxide, but it is not a substitute. Ascorbic acid is added shortly before bottling, especially to white wine. The oxygen in the wine is absorbed and ascorbic acid oxidises to dehydro-ascorbic acid. This keeps the wines fresh longer. The addition is rather negative for heavy white wines and ageable red wines. The amount in the wine is determined with chromatography or iodometry and given in mg/l. See also under agents in winemaking.

The world's largest Lexicon of wine terms.

25,804 Keywords · 47,000 Synonyms · 5,320 Translations · 31,131 Pronunciations · 175,240 Cross-references
made with by our author Norbert F. J. Tischelmayer. About the Lexicon