You poured your soap into the mold and everything looks wonderful. But, when you look at the soap the next day…ack! There’s a huge crack down the center. What happened? There are several reasons why your batch may have cracked. Below are some of the most common cracking culprits, and how to avoid them.
Too Much Hard Oils, Butters, Wax
One reason why a batch of soap might crack is because of the recipe. Soap is more likely to crack if it contains a large amount of solid oils, butters or wax. The potential for cracking is greater with more brittle butters and waxes, such as cocoa butter and beeswax. In general, I recommend limiting the amount of butters to 15% of your total oils, and the amount of beeswax to 8% or less of the total oils. This post has more information about various butters and how to use them in your soap and other beauty products.
Lots of firm butters like cocoa butter can cause soap to crack. I recommend using no more than 15% butter in your recipe to prevent this.