Hot process soap has what many call a “rustic” or less refined look, with little to no opportunity for swirling or intricate designs. However, many soapmakers love HP because of it’s quick turnaround; many soaps can be used the following day.
The hot process for soap making is very similar to the cold process. Unlike cold process soap, hot process soap does not need to be cured for a period of time. The full saponification process happens while being cooked.
Hot process uses an external heat source to bring the soap to gel phase, where it is then poured into the mold.
Unlike cold process soap, that lasts for 4-6 weeks, hot process soap can be used immediately after it hardens. However, by giving it a week or so, the bar can harden up considerably and allow an opportunity for the water to evaporate and will make a harder, longer-lasting bar.
- Saponification happens during the cooking time—there should be no leftover lye
- No need for soap to cure
- Can make transparent or liquid soap as well using this process
- Maintains the scent of scented oils
- This process takes longer to make
- Harder to make fancy soaps
- Can have air pockets in the soap
- Bar of soap doesn’t last as long as cold process soap