There are several ways of making soap.  Cold process is generally considered to be the most natural because the maker has control of the saponification process.  Saponification involves the hydrolysis of fats (triglycerides) with an alkali, such as sodium or potassium hydroxide. This reaction leads to the formation of salts of fatty acids and glycerol or soap. Controling the “trace”, or thickness of the batter, is what allows for each bar’s unique design process.  This is manipulated by factors such as water content, temperature, fragrance, and fatty acid profile.