How can I make this thicker/harder/firmer?

By using more of a thickening or hardening ingredient, and less of a liquid ingredient.

Does your recipe already contain a hard wax (beeswax, candelilla wax, carnauba wax, soy wax, etc.) or a fatty thickener (cetyl alcohol, cetearyl alcohol, stearic acid)? If so, increase the amount of that ingredient, decreasing the amount of a liquid ingredient to make room for it. Keep in mind that using more of a thickening ingredient will also bring more of the characteristics of that ingredient to the end product. For instance, increased concentrations of beeswax tends to make products stickier/skiddier.

For anhydrous products the thickening ingredient can be either a wax or a fatty thickener. You can choose to combine waxes and fatty thickeners; I’ll often do this to get some of the weight and occlusiveness of a wax like beeswax, and then get the rest of the thickening/hardening from something like stearic acid or cetyl alcohol.

For emulsions you’ll typically want to stick to fatty alcohols or pseudo-waxes (waxes where the INCI is a hydrogenated vegetable oil) as I’ve found true waxes can give emulsions a tacky skin finish. For emulsions you can also try increasing the size of the internal phase (this usually this means increasing the size of the oil phase as emulsions made with Emulsifying Wax NF, Polawax, Olivem 1000, Ritamulse SCG, and BTMS-50 are all oil-in-water emulsions).

To learn more about the potency of these ingredients and the characteristics they add to our products, check out these series of guides I’ve done:

If I haven’t done one of these guides for the thickener in your recipe it’s very simple do conduct such an experiment yourself to learn more; each of these posts details how I set the experiment up.

Good luck! Take lots of notes, label your experiments, work in small batches, and have fun!

Posted in: Troubleshooting & Adjusting