Soap is produced by mixing fats or oils with lye to produce a chemical reaction called saponification. The finished soap no longer contains lye and an end product, called glycerine, is extracted. Glycerine is then made into soap bases that can be used for melt-and-pour soap making. These soap bases, sold in bars, blocks or noodles, are a good alternative to using lye for making soap at home.
Fill your double boiler with water and bring it to a boil.
Add soap base to the top of your double boiler. If you're using a block of soap base, cut it into two-inch pieces.
Keep the burner on low heat. Stir the soap base sparingly while it melts.
Wait for the base to melt completely before adding fragrance oil. Stir the fragrance evenly throughout the soap. Fragrance oil is optional.
Pour the mixture into any size or shape moulds you prefer. If there are tiny bubbles on top of your soap, spritz with isopropyl alcohol to remove them.
Allow your soap to harden in the moulds. The time will vary based on the depth of your moulds, but it typically takes about two hours.
Remove your hardened soap from the moulds. You can use your soap right away. This recipe yields eight or nine four-ounce bars.
If you use essential oil in your soap recipe, add it before fragrance. Place your soap moulds in the freezer for 20 to 30 minutes to speed up the hardening process. You can use a microwave oven to melt the soap base. Use a bowl covered with microwave-safe cling film and heat for one minute. Wrap your soaps in paper and arrange them in a decorative basket for gift giving.
Cutting the soap base can be slippery. Use caution! Hot soap will cause burns. Be careful when handling the melted soap not to spill it on you. Also use caution when handling the hot containers. Make sure the additives you use are skin safe. Supervise older children if they are helping. Keep all tools and ingredients out of reach of young children and pets.