You’ll also need a 4-inch soap mold, a large microwave-safe measuring cup, a spoon or wooden craft stick for stirring, and optionally, a wavy soap cutter if you want a decorative edge for your bars.

Remove mold with mold-killing products. The CDC says mold can be cleaned from hard surfaces with soap and water or a bleach solution of no more than one cup of household bleach to one gallon of water.