The dictionary defines vinegar as “sour wine” or “a sour liquid obtained by acetic fermentation of dilute alcoholic liquids and used as a condiment or preservative.”
Vinegar is made by two distinct biological processes, both the result of the action of harmless microorganisms (yeast and “Acetobacter”) that turn sugars (carbohydrates) into acetic acid. Many of our favorite foods involve some type of bacteria in their production – from cheese and yogurt to wine, pickles and chocolate. The first process is called alcoholic fermentation and occurs when yeasts change natural sugars to alcohol under controlled conditions. In the second process, a group of bacteria (called “Acetobacter”) converts the alcohol portion to acid. This is the acetic, or acid fermentation, that forms vinegar. Proper bacteria cultures are important; timing is important; and fermentation should be carefully controlled.
Although acetic acid is the primary constituent of vinegar aside from water, acetic acid is not vinegar. Vinegar contains many vitamins and other compounds not found in acetic acid such as riboflavin, Vitamin B-1 and mineral salts from the starting material that impart vinegar with its distinct flavor.
Hope this explanation will be of help to you.