Thickening Saponified Liquid Soap: Alternatives to Sugar and Borax

Sugar is not effective for thickening true liquid soaps made from saponified oils and KOH because it doesn't interact with the soap structure to build viscosity significantly. Borax is also not a thickener and can cause skin dryness due to its alkalinity.

For true liquid soaps (saponified), suitable thickeners are typically water-soluble polymers or gums that are compatible with electrolytes. Two good options are Hydroxyethyl Cellulose (HEC) and Xanthan Gum.

• Hydroxyethyl Cellulose (HEC): This is a non-ionic thickener that works well in formulas containing electrolytes, such as your liquid soap. It helps create a gel texture and increase viscosity. HEC usually requires heating the water phase to around 70°C for proper dissolution and gel formation. There are different grades available offering varying viscosities.
• Xanthan Gum: This is a natural gum produced by fermentation. It is an effective anionic thickener that can be used in a wide range of formulations, including liquid soaps. It creates a clear gel texture. Xanthan Gum can be dispersed in the water phase with high-speed stirring or blending. For easier dispersion, you can mix it with a small amount of oil or glycerin before adding it to the water.

Both HEC and Xanthan Gum are effective alternatives to sugar and borax for thickening your liquid soap. The choice between them might depend on the desired texture, clarity, and ease of use (HEC requires heat, while Xanthan Gum can be dispersed in cold water but benefits from good mixing).