Sodium Hydroxide (Lye)

Functional, Actives & Additives

NaOH, Caustic Soda

Sodium hydroxide,commonly known as lye or caustic soda, is the alkali used to make bar soap through a process called saponification. It is one of the oldest and most fundamental chemical reactions in human history: when lye contacts oils and fats, it triggers a transformation that converts those raw materials into soap and glycerin. This reaction has been used to make soap for thousands of years, and it remains the only way to make true cold process bar soap.

We include lye in our ingredient library because we believe in complete transparency, and because the question "is there lye in your soap?" deserves a clear, honest answer. Yes, lye is used to make our soap. No, there is no lye in the finished bar.

How It Works

During saponification, sodium hydroxide reacts completely with the oils in our formula,the lye is entirely consumed by the chemical reaction and is no longer present in the finished soap. What remains is soap, glycerin, and any excess oils we intentionally include for conditioning (our "superfat"). A properly formulated and fully cured cold process soap contains zero free lye. The transformation is complete, irreversible, and verifiable. Finished soap has a pH of approximately 9-10, far below the highly alkaline pH of lye itself.

The information on this page is for educational purposes only. Sodium hydroxide is a caustic material handled with full safety precautions during production. It is not present in finished soap products.