Vinegar is a sour flavoring agent produced after fermentation with various kinds of leavening, chemical formula: CH3COOH , which is a weak electrolyte. Brewing vinegar mainly uses rice or sorghum as raw material. Appropriate fermentation can use the liquid containing carbohydrates (sugar, starch) into alcohol and carbon dioxide, and the alcohol is then combined with oxygen in the air by some bacteria to produce acetic acid and water. Therefore, the process of making vinegar is the process of further oxidizing alcohol into acetic acid. The flavor of vinegar is sour and mellow, and the liquid is fragrant and soft. It is an indispensable condiment in cooking, and its main components are acetic acid and high-level alcohols, etc. The main types of vinegar used now are "vinegar", "vinegar", "vinegar", and "vinegar". The main components are acetic acid and advanced alcohols, etc. Nowadays, vinegar is mainly used as "rice vinegar", "smoked vinegar", "special vinegar", "sweet vinegar", and "wine vinegar", "Wine vinegar", "white vinegar", etc. The amount of acetic acid contained in vinegar varies according to the different varieties of origin, generally between 5~8%, and the intensity of the sourness of vinegar is mainly determined by the size of the amount of acetic acid contained in it.
The main component of vinegar is acetic acid, and it also contains rich calcium, amino acid, succinic acid, gluconic acid, malic acid, lactic acid, B vitamins and salts and other nutrients which are good for the body.
Solid state vinegar method of brewing vinegar, because it is the use of nature wild microorganisms, so the fermentation cycle is long, acetic acid fermentation and the need to turn the spirits, labor-intensive. The mother of wine, alcohol fermentation, and then use the pure culture of acetic acid bacteria made of mother of vinegar, acetic acid fermentation and vinegar. There is also enzyme liquefaction, ventilation and reflux method, after soaking raw materials with water and grinding, first add bacterial α-amylase to heat and liquefy, then add brans to saccharify, saccharify the mash to cool, and add mother of vinegar to carry out alcoholic fermentation, and when the alcoholic fermentation is finished, after mixing the wine mash, brans, huller and mother of vinegar sufficiently, it is sent to the acetic acid fermentation pool with a false bottom, and there is a ventilating hole under the false bottom, which can let the air enter naturally, and make use of natural ventilation and vinegar to reflux instead of turning over the spirits. The use of natural ventilation and vinegar reflux instead of turning grains, and make the fermentation temperature of vinegar grains uniform until maturity. Enzymatic liquefaction ventilation reflux method of production, vinegar rate and labor productivity are higher than the traditional method.