acids, members of a group of chemical compounds which are responsible for the sharp or sour taste of all drinks and foods, including wine. The most important acids contained in grapes are tartaric acid and, in slightly lower concentrations, malic acid. Malic acid occurs in many different plants and fruits, but vines are among the very few plants with large concentrations of tartaric acid in their fruit. The principal acid component in most plants is citric acid but vinifera vines are also unusual among plants in accumulating only very small amounts of citric acid.
