Vinegar (from the Latin "vinum acre", "sour wine") is a water-miscible liquid, with a sour taste, which comes from the acetic fermentation of alcohol, such as that of wine and apple (through the bacteria Mycoderma aceti).

Vinegar contains a concentration ranging from 3% to 5% of acetic acid in water. Natural vinegars also contain small amounts of tartaric acid and citric acid.