unsaponified

Unsaponified refers to fats or oils that have not undergone the process of saponification. Saponification is the chemical reaction where fats or oils react with a strong alkali, such as sodium hydroxide or potassium hydroxide, to produce soap and glycerol. When a fat or oil is unsaponified, it means this reaction has not occurred, and the original fatty acids and glycerol remain largely intact.

In the context of soap making, unsaponified materials are undesirable. If a soap mixture contains a significant amount of unsaponified fats or oils, the resulting soap will be greasy, may not lather well, and can potentially irritate the skin. Soap makers aim to achieve complete saponification, ensuring that all the fatty acids have reacted to form soap molecules.

However, the term can also be used in other contexts. For instance, certain cosmetic or medicinal preparations might intentionally contain unsaponified portions of oils or butters. These unsaponified components may offer moisturizing or emollient properties, distinct from the cleansing action of true soap. Analysis of fats and oils can determine the percentage of unsaponifiable matter, which includes sterols, higher alcohols, and hydrocarbons, substances that do not react with alkali.