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How do I use my molds for Hot Process Soapmaking?

Keeping cold-process soap properly insulated is important when pouring into individual 3 and 4 ounce cavities. Heat loss can be a problem due to a large surface area relative to a small volume of soap. This heat loss can retard saponification. One solution to this potential problem is an elevated pour temperature in the range of 115-125 degrees F. Another method involves pre-cooking the soap so that it's thoroughly saponified before being poured into the molds. This is hot-process soapmaking.

What are the advantages of hot-processing? One, the soap doesn't need to be insulated since it's neutral when spooned into the molds. It just needs to cool and harden, which takes 1-2 hours. Two, neutral soap is much gentler on dyes and fragrances- you'll find both stay "truer".

I introduced a simple hot-process technique in my book Making Transparent Soap. This method can be tailored to any formulation. The steps are as follows:

1. Use two pots for soapmaking: one, your soap pot, and two, a kettle large enough to comfortably contain your soap pot. An enamel five-gallon canning pot is ideal for most situations. This second kettle will become the bottom of a double boiler. Fill it with 3-5 inches of water.

2. Stir your soap until traced. Meanwhile, bring the water in the large kettle to a slow boil.

3. After tracing, place the soap pot inside the kettle. Keep the water at a gentle boil; cover if possible to retain heat.

4. Cook your soap for 1 3/4 hours. During this time it should become a soft translucent salve. Translucency is a sign that the soap is neutralizing.

Stir briefly 2 or 3 times during cooking to ensure even heat distribution throughout the soap mass.

5. After 1 3/4 hours the soap will be neutral. Dye, fragrance and spoon into molds. If the soap seems too thick to work with, thin with a few ounces of alcohol. Start with 2-3 ounces; gradually add more if needed. Pure ethanol (Everclear), 90%-99% isopropyl or vodka all work well. When dividing the soap up for different fragrances and colors, keep the unused portion hot, or it begins hardening as it cools. Hardened soap can be "remelted" over a double boiler. And finally, any air pockets in the molded soap? These can be removed by gently tapping the mold on the counter top. Another method for removing air bubbles is to cover the top of the soap-filled cavities with a sheet of plastic film. With the palm of your hand, press the soap gently but firmly into the cavity.

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