Vinegar is an aqueous solution of acetic acid and trace compounds that may include flavourings. Vinegar typically contains from 5% to 8% acetic acid by volume. Usually, the acetic acid is produced by a double fermentation, converting simple sugars to ethanol using yeast, and ethanol to acetic acid using acetic acid bacteria.

The product is now mainly used as a flavourful, acidic cooking ingredient, or in pickling.