Sodium hydroxide, also known as Caustic Soda or Lye, is a product that is used in the creation of soap, detergent, paper, textiles and drinking water. It is a chemical base and comes packaged as a white solid.
Once the process of saponification is complete, the lye and oil molecules have combined and chemically changed into soap and glycerin. There is no lye present in the finished bars of soap or shampoo. While all real soap must be made with lye, no lye remains in our finished product after saponification.
SAPONIFICATION: THE CHEMICAL REACTION OF SOAP MAKING
If you dig deep back to your high school chemistry days, you may remember learning about acid-base reactions. When an acid and a base combine they neutralize each other and make a salt. In simple terms, saponification is the name for a chemical reaction between an acid and a base to form a salt called “soap.”
Sodium hydroxide is an alkali (base) and the acids are the fatty acids present in oils and butters. Once we select the oils and mix them with sodium hydroxide and a liquid (lye), the molecules combine, a chemical reaction occurs, called saponification (pictured below), and a totally different substance is created — SOAP!
No lye remains in our finished product!
INTERESTING NOTE ABOUT LYE!
Lye has many uses in the food industry. The secret to great pretzels is a lye bath! Lye gives pretzels their characteristic flavor, crispiness, and glossy finish. Hominy is dried corn kernels reconstituted by soaking them in lye water until the germ is removed. Lye may also be used in the preparation of olives and pickles.