I use kaolin clay in most of my soaps. Kaolin clay is a natural and gentle clay that is kind to sensitive skin but also adds slip and silkiness to soap and helps the soap’s fragrance “stick.” Some fragrances, especially citruses, don’t fare well in the harsh environment of the chemical process involved in soapmaking. Kaolin clay gives the fragrance something to “cling” to and helps the soap better retain the scent. Kaolin clay is such a fine powder that it adds the mildest exfoliation to the soap, and it’s one of the clays that works well with all skin types. Dry kaolin feels like a smooth, fine powder and is often used in cosmetics and face masks. Kaolin cleanses and detoxifies, so it really does add a little something special to soap.
I use a bit more than a teaspoon of kaolin per pound of oils in most of my recipes that don’t include other clays. For instance, in my Marseilles-style soap, which I call Provence, I use French green clay, and adding kaolin in addition would make the soap crumbly and chalky. Because the kaolin clay in my soaps is used throughout the bar and not as a colorant for a swirl, I simply add it directly to my oils before I add my lye water, and I stick blend it well to make sure the clay is dispersed and no clumps remain; however, I should add that I have not noticed that kaolin clumps a lot, unlike some other clays. You can use up to a tablespoon of clay per pound of oils, but my own experiments with clay in those amounts produced a chalky soap. Your own experiments may yield different results. My own experience is that soap with clays, including kaolin clay, feels smoother and silkier without any detrimental effects on the amount of lather.
Bonus: a picture I took just today of my Johnny Appleseed Soap, which like my other soaps, has a little over a teaspoon of kaolin per pound of oils.
Maya of Infusions and Silvia of Soap Jam have also blogged about using kaolin in their soaps.
Hello, i am a new to soap making and your blog is really helpful, thank you for sharing your knowledge :-).
I have a question about kaolin: some soap makers mix it with fragrance/essential oils to anchor the scent. Does it make much difference if at all? Also, in your opinion, does kaolin speed up trace?
Hi Ella, thank you! I don’t mix the kaolin directly with the fragrance, but one reason I use it is that it does help anchor a scent. I just mix it directly into the oils. I don’t think it speeds up trace much, if at all—not that I have ever noticed, anyway.
Would other clays work just as well as kaolin to anchor a scent?
They might, but they might also be gritty. I can’t exactly feel the grit with kaolin; it just gives a nice slip. Bentonite clay might work, too. I just don’t know since I haven’t tried other clays to anchor scent. Other soapmakers use kaolin, but it might be worth an experiment to see what else works for you!