A vinegar made by fermenting malted barley into a beer-like liquid, then fermenting it further with acetic acid bacteria into a tangy, malty condiment. It originated in Britain, where it's the traditional accompaniment to fish and chips, and is also used in marinades, salad dressings, and pickling. Its acidity is milder than wine or cider vinegar, with a distinctive malty sweetness that sets it apart from those cleaner, sharper vinegars.