Lactic Acid

Lactic acid is an organic acid with the chemical formula CH3CH(OH)COOH.
In solid form, it is white and miscible with water.
When dissolved, it forms a colorless solution.
Lactic acid is an alpha-hydroxy acid (AHA) due to the presence of a carboxyl group adjacent to a hydroxyl group.

Lactic acid is used in the pharmaceutical field to obtain water-soluble lactates from insoluble active components through various methods. It is more commonly used in topical preparations and cosmetics for acidity adjustment and disinfectant properties.
Historically, lactic acid has also been used to help erase ink from official documents that were to be altered during forgery.
Lactic acid is primarily found in sour dairy products such as yogurt, kefir, and some types of cottage cheese.
Casein in fermented milk is coagulated by lactic acid.
Lactic acid is also responsible for the sour taste of sourdough bread.