How to Harden Soft Glycerin Soap Base

To make soft glycerin soap (melt-and-pour base) harder and firmer, you should add a hardening agent. The most effective and commonly used ingredient for this purpose is Stearic Acid.

• Function: Stearic Acid is a saturated fatty acid that significantly increases the hardness and melting point of the soap bar. This results in a firmer bar that lasts longer and often produces a creamier lather.
• Usage: It must be melted completely and incorporated into the melted glycerin soap base. The typical usage rate is around 1% to 5% of the total soap base weight. Start with a lower percentage and adjust as needed.