Vinegar 醋
Vinegar is a liquid consisting of about 5–20% acetic acid (CH3COOH), water, and other trace chemicals, which may include flavorings. The acetic acid is produced by the fermentation of ethanol by acetic acid bacteria. Vinegar is now mainly used as a cooking ingredient. Historically, as the most easily available mild acid, it had a great variety of industrial, medical, and domestic uses, some of which (such as its use as a general household cleanser) are still promoted today.