September 3, 2013 by thesoapalchemist
I bet you already know that natural soap contains glycerin.
It’s one of those little byproducts of saponification that artisan soapcrafters are particularly happy to brag about. (as in, “Commercial soap companies often remove the natural glycerin from their bars and sell it to make lots and lots of money. But WE keep it in ours, which means our soap is not only better, but more moisturizing, more natural, and more everything!”).
But glycerin really is something to brag about. This naturally occurring, moisturizing humectant goes by many names including glycerin, glycerine, and glycerol. It is a naturally occurring, colorless, odorless (although, not tasteless) alcohol. In fact, glycerin has a sweetness comparable to sugar, yet contains no sugar. It is often used as a sweetener for people who cannot consume regular sugar, including diabetics and those suffering with Candida.
The amount of glycerin that is created in a bar of natural soap varies from about 6-16% of the total oils used in the recipe. I have yet to determine what creates this difference, but I suspect it has something to do with the oils used and their SAP values, the amount of lye used, and possibly even the type of lye (be in NaOH or KOH) used in the recipe. Recently, I created an experimental soap using honey and sugar along with some other interesting ingredients, such as lactic acid, vitamin E and comfrey.
This soap “bleeds” glycerin. I leave in propped on its side in the soap dish, and the glycerin absolutely oozes out, leaving a puddle of lovely moisturizing goo. I haven’t had this happen before. It’s a soft soap, most likely due to the high sugar content, but the glycerin is unusually abundant. It’s been fully cured for over a month, and is a wonderfully conditioning soap. I’ve been really happy with the way my skin feels after using it, and I’m amazed by the amount of glycerin that comes out of it. I tried searching the web for explanations of what might be creating the excess glycerin, but so far, I am unable to find any definitive explanation. If those commercial soap companies that extract and sell their glycerin only had my secret recipe… 🙂