Vinegar is created through the fermentation of ethanol by acetic acid bacteria. When a slow fermentation method is used, the process takes anywhere from two months to a year. With a quick fermentation process, typically used for commercial vinegars, a bacterial culture called "mother of vinegar" is added to the ethanol liquid, and then air is added. Vinegar can be made this way in as little as 20 hours.
Vinegar can be made from any natural sugar that is turned into alcohol. Once the sugar has been fermented into alcohol by the use of yeast, a second fermentation converts the alcohol to acetic acid. White vinegar is made from corn, and wine vinegars are made from wine. Apples, berries, coconuts, grapes, barley, potatoes, rice and wheat are all used as the basis for vinegar. Once the alcohol has been converted to vinegar, it is diluted with water until it reaches a 5 percent acidity level.
Vinegar is used for pickling and in salad dressings, particularly vinaigrette dressings. It is also used as an ingredient in ketchup, chutney, mint sauce, sushi rice, marinades and mayonnaise. It is sometimes even used as a condiment on its own. Because it has such a high acidic content, it has an indefinite shelf life even without refrigeration.