How Soap Works
Jul 19, 2019 Updated July 19, 2019. Soaps are sodium or potassium fatty acids salts, produced from the hydrolysis of fats in a chemical reaction called saponification. Each soap molecule has a long hydrocarbon chain, sometimes called its tail, with a carboxylate head. In water, the sodium or potassium ions float free, leaving a negatively-charged head.