Heat & hold
Heating the water and oil phases separately to 70°C and holding for 20 minutes before emulsifying.
“Heat and hold” is a foundational technique in cosmetic formulation. Both phases are heated to 70°C and held there for at least 20 minutes before they are combined.
There are three reasons:
- To dissolve and melt all ingredients fully — gums, fatty alcohols, waxes, butters.
- To reduce microbial load — sustained heat kills the bacteria that may be hiding in raw materials.
- To stabilize the emulsion — combining two phases at the same temperature is critical for a smooth, stable cream.
Skip the hold at your peril: skipped heat-and-holds are one of the most common reasons home-made creams develop mold or separation.