About Soap Making
Curious about the chemistry behind soap making? “Saponification” refers to the chemical reaction between fat and lye that results in the formation of glycerin and soap. Saponification occurs when, first, three molecules of sodium hydroxide (NaOH) are dissolved in water (H2O) and are split apart, which results in three sodium ions (Na) and three hydroxyl groups (OH). Second, a triglyceride (fat) molecule (C3H5(COOR)3) is split apart through hydrolysis, which results in a free glycerol (C3H5) and three fatty acid tails (COOR). Third, the hydroxyl groups all bond to the free glycerol to form a molecule of glycerin. Fourth, the three fatty acids each bond with one of the three sodium ions to form three molecules of soap (3NaCOOR). When the ingredients have completed the saponification process, one molecule of glycerin will be present for each three molecules of soap; no molecules of lye (sodium hydroxide) remain in the soap—they have all been split apart and used to form the soap molecules and glycerin.