VINEGAR

Vinegar is an acidic liquid processed from the fermentation of ethanol in a process that yields its key ingredient, acetic acid (also called ethanoic acid). It also may come in a diluted form. The acetic acid concentration typically ranges from 4 to 8 percent by volume for table vinegar (typically 5%) and higher concentrations for pickling (up to 18%). Natural vinegars also contain small amounts of tartaric acid, citric acid, and other acids. Vinegar has been used since ancient times and is an important element in European, Asian, and other traditional cuisines of the world.

Vinegar is made from the oxidation by acetic acid bacteria of ethanol in wine, cider, beer, fermented fruit juice, or nearly any other liquid containing alcohol.Commercial vinegar is produced either by fast or slow fermentation processes. Slow methods generally are used with traditional vinegars and fermentation proceeds slowly over the course of weeks or months. The longer fermentation period allows for the accumulation of a nontoxic slime composed of acetic acid bacteria and soluble cellulose, known as the mother of vinegar.Fast methods add mother of vinegar (i.e. bacterial culture) to the source liquid before adding air using a Venturi pump system or a turbine to promote oxygenation to obtain the fastest fermentation. In fast production processes, vinegar may be produced in a period ranging from 20 hours to three days.

Vinegar eels (Turbatrix aceti), a form of nematode that has cells that are air-borne, may occur in some forms of vinegar unless the vinegar is kept covered. These feed on the mother of vinegar and can occur in naturally fermenting vinegar. This is the reason vinegar condiment jars have tightly-fitting stoppers. Most manufacturers filter and pasteurize their product before bottling to eliminate any potential adulteration, although they are harmless when ingested.

Fruit vinegars are made from fruit wines, usually without any additional flavoring. Common flavors of fruit vinegar include apple, black currant, raspberry, quince, and tomato. Typically, the flavors of the original fruits remain in the final product. Most fruit vinegars are produced in Europe, where there is a growing market for high-priced vinegars made solely from specific fruits (as opposed to non-fruit vinegars which are infused with fruits or fruit flavors). Several varieties, however, also are produced in Asia. Persimmon vinegar, called gamsik cho (감식초), is popular in South Korea. Jujube vinegar and wolfberry vinegar are produced in China.