Hey all!
Inspired by this recipe Lots & Lots of Clay Soap - Humblebee & Me I wanted to see how different amounts of kaolin clay changed soap.
Originally, I was trying to see how much it took to make soap noticeably whiter. I failed to take water absorption into account, and got some interesting results.
I used this recipe How to Make Gentle Hemp and Shea Soap - Humblebee & Me because it was high in hemp oil which was supposed to make the soap a little darker than normal, making it good for testing whitening.
I split the batter into 4:
- 0 clay
- 2 tbsp per pound of oils
- 4 tbsp per pound of oils
- 8 tbsp per pound of oils
Unfortunately, my SB was broken, so it was hand mixed, and not very well. On top of that, I did not know that you’re supposed to mix the clay with water before you add it.
This is what I got:
The layers are in order, such that the top had the most clay and the bottom had none. Completely backwards to my expectation of whitening. And even more than lightening, the clay increased the green hue of the oil.
I had two hypotheses as to what could have caused this: 1) the clay somehow increased gel 2) the clay was absorbing the water, creating the same effect as “ghost swirls”.
I tested again adding 2 tbsp of kaolin clay per pound, this time in 100% CO soap with colored additives, and forced the gel phase in the oven, and left some soaps outside in the cold:
The top row is soap without clay in the oven; the middle soap is with clay in the oven, and the bottom row is soap with clay out in the cold. This time, I mixed the clay with some water first.
Clearly, the clay actually did lighten the soaps a bit, even in the oven, which means that it wasn’t the gel, it was the water (I think).
Then after two months I did a literal blindfolded test of the soap with different clay amounts:
(as you can see, the soap with no clay at the bottom developed more soda ash, supporting the idea that the soap with a lot of clay had less water available)
Maybe my hands are completely insensitive, but I was not able to pick up a noticeable difference between the soaps except a slight change in texture.
We recently got through our first soap with all the layers, and there was again no noticeable difference, like either the top or bottom dissolving more quickly.
When I followed the original Lots and Lots of clay recipe with French Green Clay, which uses about 10 tbsp per pound of oil, I actually got a substantially rougher texture, which I quite liked, as well as a bar that hardened really quickly, so already a month after curing it was ready to use, and had a nice creamy lather, dark green color, and strong scent.
So in conclusion, you can add a LOT of kaolin clay, it just may not actually change much. I had more of an effect with green clay.
Inspired by this recipe Lots & Lots of Clay Soap - Humblebee & Me I wanted to see how different amounts of kaolin clay changed soap.
Originally, I was trying to see how much it took to make soap noticeably whiter. I failed to take water absorption into account, and got some interesting results.
I used this recipe How to Make Gentle Hemp and Shea Soap - Humblebee & Me because it was high in hemp oil which was supposed to make the soap a little darker than normal, making it good for testing whitening.
I split the batter into 4:
- 0 clay
- 2 tbsp per pound of oils
- 4 tbsp per pound of oils
- 8 tbsp per pound of oils
Unfortunately, my SB was broken, so it was hand mixed, and not very well. On top of that, I did not know that you’re supposed to mix the clay with water before you add it.
This is what I got:
The layers are in order, such that the top had the most clay and the bottom had none. Completely backwards to my expectation of whitening. And even more than lightening, the clay increased the green hue of the oil.
I had two hypotheses as to what could have caused this: 1) the clay somehow increased gel 2) the clay was absorbing the water, creating the same effect as “ghost swirls”.
I tested again adding 2 tbsp of kaolin clay per pound, this time in 100% CO soap with colored additives, and forced the gel phase in the oven, and left some soaps outside in the cold:
The top row is soap without clay in the oven; the middle soap is with clay in the oven, and the bottom row is soap with clay out in the cold. This time, I mixed the clay with some water first.
Clearly, the clay actually did lighten the soaps a bit, even in the oven, which means that it wasn’t the gel, it was the water (I think).
Then after two months I did a literal blindfolded test of the soap with different clay amounts:
(as you can see, the soap with no clay at the bottom developed more soda ash, supporting the idea that the soap with a lot of clay had less water available)
Maybe my hands are completely insensitive, but I was not able to pick up a noticeable difference between the soaps except a slight change in texture.
We recently got through our first soap with all the layers, and there was again no noticeable difference, like either the top or bottom dissolving more quickly.
When I followed the original Lots and Lots of clay recipe with French Green Clay, which uses about 10 tbsp per pound of oil, I actually got a substantially rougher texture, which I quite liked, as well as a bar that hardened really quickly, so already a month after curing it was ready to use, and had a nice creamy lather, dark green color, and strong scent.
So in conclusion, you can add a LOT of kaolin clay, it just may not actually change much. I had more of an effect with green clay.
