Neutralize the Liquid Soap
Post by Sparklyn, 10-Jan-2025.
In addition to the different alkali, and the cooking of the soap, liquid soap is different from bar soap in the way it is formulated. If you run most recipes through a lye calculator you will see that there seems to be way too much lye! Indeed, liquid soap recipes are usually formulated with about a 10% lye excess. This is to ensure that all of the oils are saponified.
After the soap paste has completely dissolved in the water, it is time to neutralize the soap and add your fragrance. Turn the crock pot back on and bring the mixture back up to 180 degrees or so.
In a separate container, mix the neutralizing solution. You can make either a 20% boric acid solution or a 33% Borax (20 Mule Team) solution. For the boric acid, take 8 oz. of boiling water and add 2 oz. boric acid. For the Borax, use 3 oz. Borax in 6 oz. of boiling water. It is important to stir very well and make sure that it stays very hot. As this mixture cools, the Borax or boric acid will start to precipitate out of the mixture and it will not mix into your soap!
Add about 3/4 oz. of neutralizer for every pound of soap paste (just the paste, not the added water.) So, for this recipe which has about 2.8 lb. of paste, add 2 oz. (2.13 rounded down to 2) of neutralizer solution. Too much neutralizer (especially the boric acid solution) can cause cloudiness, so it is best to round down and err on the conservative side.
Slowly pour the neutralizer into the re-heated soap mixture and stir well. Add one ounce first and let it sit for a bit. Then add another half ounce. Then, if you still have no cloudiness, add the final half ounce.