Acetic acid, also known as acetic acid (36%-38%) and glacial acetic acid (98%), is an organic monobasic acid and the main component of vinegar. Pure anhydrous acetic acid (glacial acetic acid) is a colorless hygroscopic solid with a freezing point of 16.6℃(62℉). After solidification, it is a colorless crystal, and its aqueous solution is weakly acidic and corrosive. Steam can irritate eyes and nose.
Acetic acid is widely distributed in nature, such as fruits or vegetable oils, but mainly exists in the form of esters. It exists in animal tissues, excreta and blood in the form of free acid. Many organisms can convert different organic substances into acetic acid by fermentation.
Acetic acid is the main component of vinegar, which almost runs through the whole history of human civilization. Acetic acid fermenting bacteria (Acetobacter) can be found in every corner of the world. Every nation will inevitably find vinegar when making wine-it is the natural product of these alcoholic drinks exposed to the air. In China, for example, there is a saying that Heita, the son of Du Kang, was jealous because he had been brewing for too long.