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Hot Process Crock Pot Soap


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Hot Process Soap - in the Crock Pot
hot process crock pot soap

Equipment and ingredients for crock pot hot process soap

David Fisher
In the world of soap making, there are several processes or styles of soap making. There’s melt and pour which uses a pre-made base that you melt and add fragrance and color too. There’s cold process which mixes the melted oils and lye together but doesn’t add any additional heat. The saponification process makes its own “heat” and the soap hardens and saponifies over night. Then there is hot process soap which mixes the oils and lye – and then adds extra heat to jump start the saponification process and basically “cooks” the soap to completion.

Where in cold process soap, the saponification process takes 24-36 hours to complete, with hot process, the saponification is done when the soap is done cooking. It may seem an odd addition of extra work...but there are a couple of benefits of hot process soap:

  • Since you add fragrance and additives after the soap has cooked, they do not come in contact with the lye. This can be more gentle on fragile fragrance oils, and can reduce the lye’s effect on botanicals like flower petals and lavender buds which turn brownish black when they contact the lye.
  • The soap is ready to use sooner – the process cuts a day off of the saponification process and (depending on how much water you use in your recipe) can cut down on the cure time needed
  • The soap has a rougher, more rustic look to it – which can be desirable with some soap recipes.
Pioneer soap makers, boiling their soap in big kettles over an open fire were basically doing a hot process soap – cooking the soap in the pot. You can also hot process a batch of soap in the oven. This method uses a crock pot to cook the soap.

You can use pretty much any soap recipe to make hot process soap. The only caveat is that you want to use the full amount of water. Since you're going to be cooking the soap, some of the water evaporates...so you don't want to skimp.

For this recipe, which made about 4.5 pounds of soap, I used:

  • coconut oil – 14.6 oz. – 30%
  • olive oil – 13.7 oz. – 28%
  • lard – 11.7 oz. – 24%
  • almond oil – 3.9 oz. – 8%
  • castor oil – 2.4 oz. – 5%
  • cocoa butter – 2.4 oz. – 5%
  • 6.8 oz. lye – 6% lye discount
  • 17 oz. water – (no water discount)
  • 2 oz. of fragrance or essential oil
I also added the following optional ingredients:
  • 2 tbs. of rhassoul clay
  • 1/2 tsp. of green oxide
  • 1 tsp. of silver mica

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