Vinegar (formerly also called ) is an aqueous solution of acetic acid and trace compounds that may include flavorings. Vinegar typically contains from 5% to 8% acetic acid by volume. Usually, the acetic acid is produced by a double fermentation, converting simple sugars to ethanol using yeast, and ethanol to acetic acid using acetic acid bacteria. Many types of vinegar are made, depending on source materials. The product is now mainly used in the culinary arts as a flavorful, acidic cooking ingredient, or in pickling. Various types are used as condiments or garnishes, including balsamic vinegar and malt vinegar. As the most easily manufactured mild acid, it has a wide variety of industrial and domestic uses, including functioning as a household cleaner. Etymology The word "vinegar" arrived in Middle English from Old French (vyn egre; sour wine), which in turn derives from Latin: (wine) + (neuter gender of , sour). The word "acetic" derives from Latin (vinegar). Chemistry The conversion of ethanol (CH3CH2OH) and oxygen (O2) to acetic acid (CH3COOH) takes place by the following reaction: CH_3CH_2OH + O_2->CH_3COOH + H_2O Polyphenols Vinegar contains numerous flavonoids, phenolic acids, and aldehydes, which vary in content depending on the source material used to make the vinegar, such as orange peel or various fruit juice concentrates. History While vinegar making may be as old as alcoholic brewing, the first documented evidence of vinegar making and use was by the ancient Babylonians around 3000 BC. They primarily made vinegar from dates, figs, and beer and used it for both culinary and medicinal purposes. Traces of it also have been found in Egyptian urns. In East Asia, the Chinese began professionalizing vinegar production in the Zhou dynasty. The book Zhou Li mentions that many noble or royal households had a "vinegar maker" as a specialized occupation. Most vinegar-making then was concentrated in what is now Shanxi province near the city of Taiyuan, which remains a famous vinegar-making region today. Many Chinese kinds of vinegar and their uses for culinary and medicinal purposes were written down in the agricultural manual Qimin Yaoshu (齊民要術). The Greeks and Romans frequently used vinegar made from wine. The Spartans had vinegar as a part of their traditional broth melas zomos. The Roman Columella described the ingredients and process for making several types of vinegar in his work Res Rustica. In the late Middle Ages, vinegar making was slowly being professionalized