Sodium hydroxide

Sodium hydroxide (NaOH), also known as lye or caustic soda, is a strong alkaline compound used solely for soapmaking. It is essential in the process of turning oils and butters into soap.

Why?

  • Reacts with oils in a process called saponification, producing soap and natural glycerin
  • Allows the creation of solid, stable, cleansing soaps

Completely disappears once the reaction is complete — there is no NaOH left in the finished soap