Acetic Acid

Acetic Acid is an acid that results when wine or cider are allowed to ferment. First, alcohol is produced and then if fermentation is allowed to continue, acetic acid. The bacteria that causes it is called acetobacter. Acetic Acid is very sour.

Pure Acetic Acid is clear with no colour. The smell is very irritating to the nose. The liquid is extremely corrosive to skin and it is not safe to consume. It will freeze at 16.7 C (62 F) and boil at 118°C (244 F.)

Pure Acetic Acid is used industrially. When it is used in combination with cellulose it makes cellulose acetate, which film and rayon are made from. Aspirin (acetylsalicylic acid) is made from Acetic Acid and salicylic acid.

When diluted, Acetic Acid is called “vinegar.” It is what gives vinegar both its sharp smell and sour taste. Most commercial, food grade vinegars these days contain between 4 to 8 % Acetic Acid. Agricultural use vinegars can have percentages of around 15 to 20%.

History Notes

Acetic Acid was first isolated at the start of the 1700s by distilling vinegar.

Language Notes

The name, “acetic”, comes from the Roman’s word for vinegar, which was “acetum”.