When you mix lye with fats or oils, a chemical reaction occurs. When the process is completed, you no longer have any fat or lye and are left with soap! This process is known as saponification.
A manmade ingredient, lye on its own is incredibly caustic. When using it, it comes with many warnings and for good measure. When mishandled or used incorrectly, it can cause chemical burns on the skin and permanent damage to your eyes. It also emits extremely strong fumes once initially mixed with water that you don’t want to inhale. By practicing the right safety, you can easily use lye at home to make soap. Once you successfully mix the lye and the oils together, the chemical reaction means there’s no lye left in the final product.
Melt and pour soap is prepared using a pre-made base which is melted down and—after having your preferred combination of fragrance and colour added—poured into a mold where it hardens and becomes a ready-to-use soap. Melt and pour is the easiest and quickest soap-making method because it skips the complicated step of saponification and gets you straight into the fun stuff: personalizing your soap with fragrance, colour, and other additions.