In soap, clay is a super-secret but incredibly effective ingredient. It serves as a natural, gentle exfoliant, as well as a way to remove oils and impurities from your skin. Extra perk: Its silkiness makes shaving easier, too. You can add kaolin clay to soap, or you can choose another variety for different benefits.
Varieties of Clay
Some of the most common clays used in soap include kaolin, bentonite, rose clay, and rhassoul. Each one has a slightly different quality that might make you choose one over the other.
- Kaolin: Kaolin is a mild, white, fluffy clay. It's good for light masks or scrubs and gives a silkiness and creaminess to soaps. It is good to use on dry or sensitive skin. It is used in facials, natural deodorants, and poultices.
- Bentonite: Bentonite is highly absorbent and good for oily skin, though it's technically volcanic ash rather than clay. It gives a slippery silkiness which makes it good a good additive in shaving soaps.
- Rose clay: A general-purpose clay used mostly for its lovely rose color, it also adds silkiness, slip, and absorbency to soaps. This clay cleanses and detoxifies, exfoliates dead skin cells, treats acne and sun-damaged skin, and can increase blood circulation to the skin.
- Rhassoul: This is a light brown clay that has used for its great ability to absorb oils and impurities from the skin and hair. It gives a lovely brown speckled color and is lightly exfoliating. This clay has been found to improve clarity and elasticity of the skin. It is also good for an oily complexion.
You can use the same recipe with the different clay ingredients, as it's all about the ratio: Use 2 teaspoons of clay for every pound of oil. For a recipe that has about 53 ounces of oils, you will use slightly more than 2 tablespoons of clay in each of the batches. The oil composition is as follows:
Methods for Mixing
Because clay is an inert substance, you can add it at any time during the process, as long as it gets mixed in completely. If you were to dump the clay right into the pot, you would have to deal with a lot of lumps, so start in small amounts and use a small whisk to mix well.
Add Clay to Oil
In general, this is probably the method that works best, especially if you're not using the clay as a colorant to do any sort of swirl. Once your oils have all melted, just add the clay directly to the melted oils. Use your stick blender to make sure that it is completely incorporated. Look for clumps sitting on the bottom of the pot. Once the clay has been dispersed throughout the oil, just add your lye-water and proceed as you normally would.
Add Clay to the Lye Water
This works best with lighter clays like kaolin, but sometimes the heavier clays won't dissolve well in the water and will tend to clump.
You might want to avoid this method for your first time. There is the danger of splashing the lye when you're mixing.
Make a Slurry of Oil and Clay
This is the method you would want to use if you wanted a more variegated or mottled color in your soap or to do a swirl. Once your oils have melted, add your lye-water solution. Just stir it gently until the lye and oils are lightly mixed together, but do not mix too much. Ladle out a cup or two of the lightly mixed raw soap and put it into a large measuring cup or bowl, then add the clay and mix well. Mix the rest of the soap in the pot until it is almost time to pour. Then you can stir the colored reserve of soap back into the pot and make a swirl. Alternatively, you can pour the uncolored soap into the mold and layer or swirl the colored mix into it for an even more defined swirl. The challenge with this method is getting one large portion and one small portion of soap to trace at the same time, and you need to work quickly.