Hot Process Soap Recipe

A simple hot process soap recipe cooked in a slow cooker. Usable sooner than cold process soap.

Why this recipe works

Cooking the soap finishes saponification in about an hour, so the bars are safe to use sooner. The texture is rustic rather than smooth.

Ingredients

Amounts are for 1000 g (or 32 oz) of oils, a batch of about 1421 g before curing. Water is 2:1 to lye by weight.

Method

1. Put on gloves and eye protection and clear the work area.
2. Weigh the water into a heat-safe jug. Weigh the lye separately, then slowly add the lye to the water, never the other way round. Stir until dissolved.
3. Melt the oils in a slow cooker on low.
4. Add the lye solution to the oils and stick blend to trace.
5. Cover and cook on low, stirring every 15 minutes, until the soap looks like translucent mashed potato or petroleum jelly.
6. Let it cool slightly, stir in fragrance and additives, then press into the mould.
7. Unmould once firm (usually the next day), cut and let the bars dry.

Tips

• Cook on low in a slow cooker until the soap looks like translucent mashed potato, usually 45–90 minutes.
• Add fragrance after cooking, when the soap has cooled slightly, so less of it evaporates.
• The bars are usable after about a week, but a 2–4 week cure gives a harder, longer-lasting bar.

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