The preparation of glacial acetic acid can be done by two methods: artificial synthesis and bacterial fermentation. The biosynthesis method, which uses bacterial fermentation, accounts for only 10% of the world’s production, but it is still the most important method for the production of acetic acid, especially vinegar, because many countries’ food safety regulations require that vinegar in food must pass the biological method. Preparation, and fermentation method is divided into aerobic fermentation method and anaerobic fermentation method.
With sufficient oxygen, Acetobacter bacteria can produce acetic acid from foods containing alcohol. Commonly used is cider or wine mixed with cereals, malt, rice or potatoes and mashed and fermented. The chemical equation for the fermentation reaction of these bacteria is:
C₂H5OH + O₂ →CH₃COOH + H₂O