🍷 Tartaric acid

Tartaric acid is the main acid of grapes. It is rare in nature, and among fruits grapes are especially rich in it. It gives juice and wine freshness and sharpness. That is why wine acidity is discussed mostly in relation to it.

Tartaric acid matters to wine for several reasons. It helps the wine keep from spoiling, supports the bright colour of red wine and gives a fresh taste. In hot regions grapes have little acid, and a winemaker may add tartaric acid. This is called acidification. When wine is chilled, the acid forms a salt, tartar, as small crystals on the bottle bottom or the cork. They are harmless.

Tartaric acid is sharp and comes from the grapes. Lactic acid, formed from malic acid in a special fermentation, is soft and comes from bacteria. Tartaric acid is part of the idea of acidity. It is what sets the taste of grape wine apart from many other fruit drinks.