Vinegar may be started by the addition of mother of vinegar to wine or cider. The oxidation is carried out by acetic acid bacteria, as was shown in 1864 by Louis Pasteur.
It is commonly used in food preparations, particularly in vinaigrettes, and in the pickling process. It is also used as a condiment. For example, the British and Americans commonly use malt vinegar on fish and chips.
Malt vinegar is made by malting barley, causing the starch in the grain to turn to sugar. An ale is then brewed from the sugar and allowed to turn into vinegar, which is then aged. A cheaper alternative, called 'non-brewed condiment', is a solution of 4-8% acetic acid coloured with caramel.
White vinegar can be made by distilling malt vinegar, or may be nothing more than a solution of acetic acid in water.
Italian balsamic vinegar, made around Modena in Italy from white Trebbiano grape juice, is used in salad dressings, ice cream, marinades and drinking. It is aged for several years in wooden barrels to give it a dark color and sweet flavour.
The Japanese prefer a more delicate rice vinegar and use it for much the same purposes as Europeans.
Vinegar is a folk medicine used in China to prevent the spread of virus such as SARS (Severe Acute Respiratory Syndrome) and other pneumonia outbreaks:
"On February 13, 2003 news of a type of atypical pneumonia that appeared in six cities of south China's Guangdong province has been brought under control, with no cases reported since Monday. According to press conferences held by the Guangdong and Guangzhou governments, local governments at various levels have taken emergency measures to control the prices of isatis root, vinegar and other related anti-virus medicines, which saw soaring prices due to their effectiveness in curing this disease." Source Unknown
Vinegar along with hydrogen peroxide (H2O2) is used in livestock industry to kill bacteria and viruses before refrigeration storage. A chemical mixture of peracetic acid is formed when acetic acid is mixed with hydrogen peroxide. It is being used in some Asian countries by aerosol sprays for control of pneumonia. Usually of a 5% acetic acid and a 3% hydrogen peroxide is commonly used.