True soap is a gentle cleansing agent made up of three ingredients in various combinations: fats or oils (which are acidic), a base or alkali (most often sodium hydroxide or lye), and pure water. When the oils and the lye are slowly and gently mixed together, a chemical reaction takes place. This process is called saponification. The molecules separate and reattach themselves in a new and different pattern creating a new substance called soap. After pouring raw soap, the saponification process is complete after 24 to 48 hours. Curing the soap bars for a minimum of four weeks furthers the chemical reaction, creating a hard, longer lasting bar that cleans and nourishes your skin.