|What is it?||Sodium Stearate is saponified stearic acid—the sodium salt of stearic acid.|
|Appearance||Fine white powder|
|Approximate Melting Point||245–255° C|
|Solubility||Water, alcohol, cosmetic esters|
|Why do we use it in formulations?||Sodium Stearate has a couple of really neat uses in cosmetics. It functions as a thickener/gelling agent and co-emulsifier. You’ll commonly find it in deodorants, where it is combined with propylene glycol or propanediol to create a solid stick base that actives can be added to.|
|Do you need it?||No, but if you have a formulation that calls for it there’s no substitution.|
|Refined or unrefined?||Sodium stearate only exists as a refined product.|
|Strengths||Excellent thickener/gelling agent.|
|Weaknesses||Harder to source than many ingredients, high pH.|
|Alternatives & Substitutions||I haven’t found any viable alternatives for sodium stearate when used as a gelling agent with propylene glycol/propanediol.
As a thickener, you might try stearic acid, but keep in mind stearic acid is not water-soluble like sodium stearate is.
|How to Work with It||Slowly sprinkle sodium stearate into the hot aqueous phase to dissolve, whisking to incorporate.|
|Storage & Shelf Life||Stored somewhere cool, dark, and dry, sodium stearate should last at least two years.|
|Tips, Tricks, and Quirks||Sodium stearate + propylene glycol or propanediol creates a very cool semi-translucent gelled solid!|
|Recommended starter amount||100g (3.5oz) or less.|
|Where to Buy it||Buy it from an online DIY ingredient supplier or Amazon.|