The Chemistry of Lye and Soap Making

Lye is the common name for sodium hydroxide, a strong base essential in soap making.
Soap is created through saponification, a reaction between lye and fats or oils.
During saponification, triglycerides in fats break apart into glycerol and soap molecules.
Soap molecules have two ends: one bonds with water, the other with oil and grease.
This dual nature allows soap to lift dirt and oils off skin and surfaces.
The glycerol formed in the reaction adds moisture, making soap gentler on skin.
Different oils, like olive or coconut, give soaps unique textures and lather qualities.
Proper ratios of lye to fat are critical—too much lye makes soap harsh and caustic.
Cold-process soap making lets the reaction happen slowly, creating creamy bars.
Behind every bubble is chemistry—bases turning fats into one of humanity’s oldest cleansers.