When we make our cold-processed handmade sodium hydroxide (lye) is mixed with water or another water-based liquid.
This lye water reacts with fats (the plant oils and butters) to create soap in a natural chemical reaction called saponification.
When saponification is complete, the lye and oil molecules have combined and chemically changed into soap and glycerin.
All real soap is made with lye. No lye--no soap. Any skin or hair cleansing product made without sodium hydroxide is not soap, it is a detergent.
If the soap is made properly, the lye is used up in the saponification process to turn oil into soap and there is no lye present in the finished bars of soap or shampoo.
"Is There Lye In Natural Soap? Won't It Harm My Skin?" Learn more about the Chemistry of Soapmaking in our blog