Customers often ask us which kind of soap they should buy: which is the most moisturizing, which will last the longest, which is the most gentle. Choosing from among different bar soaps can be overwhelming. And depending on an individual’s concerns, as well as their body chemistry, the answer to this question varies.
Over the next few posts we’ll unpack this question a bit, and we’ll go in-depth to discuss how different soaps are made. First, we’ll talk about simple cold process soaps, such as vegetable glycerin soaps.
Bar soaps are a mixture of an acid (any combination of fats such as olive oil, coconut oil, etc.), a base (typically lye), and water. When these ingredients combine, a chemical reaction called saponification occurs: triglycerides from the oil combine with lye to release glycerol, and the acid combines with the base to form a salt. Glycerol becomes glycerin, and the salt eventually cools down to become the soap bar.
But the choice of fats, the amount of heat added, and the mixing process are all factors that determine what kind of soap you end up with.