<P> Vinegar is a liquid consisting of about 5--20% acetic acid (CH COOH), 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, or in pickling . As the most easily manufactured mild acid, it has historically had a great variety of industrial, medical, and domestic uses, some of which (such as its use as a general household cleaner) are still commonly practiced today . </P> <P> Commercial vinegar is produced either by a fast or a slow fermentation process . In general, slow methods are used in traditional vinegars where fermentation proceeds slowly over the course of a few months or up to a year . The longer fermentation period allows for the accumulation of a non-toxic slime composed of acetic acid bacteria . Fast methods add mother of vinegar (bacterial culture) to the source liquid before adding air to oxygenate and promote the fastest fermentation . In fast production processes, vinegar may be produced in between 20 hours to three days . </P>

What is the percentage of acetic acid in vinegar