Science, Tech, Math › Science What Is the Chemical Composition of Vinegar? Acetic Acid and Other Compounds in Vinegar Share Flipboard Email Print Acetic acid is the primary acid in vinegar. Cacycle, Wikipedia Commons Science Chemistry Molecules Basics Chemical Laws Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated June 04, 2019 Vinegar is a liquid that is produced from the fermentation of ethanol into acetic acid. The fermentation is carried out by bacteria. Vinegar consists of acetic acid (CH3COOH), water and trace amounts of other chemicals, which may include flavorings. The concentration of the acetic acid is variable. Distilled vinegar contains 5-8% acetic acid. Spirit of vinegar is a stronger form of vinegar that contains 5-20% acetic acid. Flavorings may include sweeteners, such as sugar or fruit juices. Infusions of herbs, spices and other flavors may be added, too. Vinegar is made from a variety of source materials. Each contributes its own unique flavor signature to the final product. Vinegar may be made from sugar cane juice, rice and other grains, grapes (balsamic vinegar), coconut water, fruit wines, kombucha, or apple cider. Spirit vinegar is a strong variety of vinegar (5% to 21% acetic acid) made from sugar cane and doubly fermented. The first fermentation changes sugar into alcohol, while the second fermentation changes alcohol into acetic acid. Sources Bourgeois, Jacques; Barja, François (December 2009). "The history of vinegar and of its acetification systems." Archives des Sciences. 62 (2): 147–160.Cerezo, Ana B.; Tesfaye, Wendu; Torija, M. Jesús; Mateo, Estíbaliz; García-Parrilla, M. Carmen; Troncoso, Ana M. (2008). "The phenolic composition of red wine vinegar produced in barrels made from different woods". Food Chemistry. 109 (3): 606–615. doi:10.1016/j.foodchem.2008.01.013Nakayama, T. (1959). "Studies on acetic acid-bacteria I. Biochemical studies on ethanol oxidation". J Biochem. 46 (9): 1217–25.