Soap: Olive and Coconut Oils
I decided to start with olive oil, because I had a bunch of it, it was relatively cheap (especially for the lower grades–you get no benefit from extra-virgin in soap; I just used it because I had it around), and it makes a classic soap.
You’ll frequently see people advertising “Castile” soap. This comes from the days when Castilian soapmakers had a lot more olive oil than they did tallow (the standard soapmaking fat in those days), and figured out that they could make some very mild, high-quality soap with it. These days, people add all sorts of other stuff, but all castile soaps are based on olive oil.
Olive oil’s saponification number is 0.134, so the recipe will be:
100 g olive oil
38 g water
13.4 g lye.
My scale only reads down to 1 gram precision, so I stuck with 13 grams to avoid having too much lye in the soap. I measured out ingredients in a beaker from Ingvar Kamprad Scientific Supply.
After a few minutes, I decided to call it. It looked a little thicker, and that’s about all you can hope for with 100% olive.
I poured it into the ice-cube tray I had waiting. The soap was the color of mustard, which shouldn’t have been all that surprising, but the resemblance was striking.
My next victim was the anti-olive oil: coconut.
| Olive oil | Coconut oil |
| Makes very soft soap | Makes very hard soap |
| Soap is skin-friendly | Soap dries out skin |
| Soap lathers very little | Soap is very sudsy |
| 14% saturated fat | 86% saturated fat (!) |
| Supposed to be healthy for you (Mediterranean diet, antioxidants, etc.) | Will leap out of jar and jam your aorta like the 101 during rush hour if provoked |
| Liquid at room temperature | Solid at room temperature, and actually forms largish crystals to boot |
Here’s a picture of the end of the jar, showing the crystals:
And yes, it was much harder. It was almost a slurry when I poured it out of the blender, and I didn’t run it for nearly as long. Oh, ingredients:
100 g coconut oil
38 g water
19 g lye (saponification number 0.190)
Here’s what the liquid coconut oil looked like after I stuck it in the microwave for a while:
And here’s the final product. The olive-oil soap was a little darker, but not quite as dark as it looks in this picture. The coconut-oil soap looks like it’s at least firm in this shot, and it is. It sets up very hard, and very fast:
Prior: Background.
Next: Mixed oils, walnut, and more!
9 comments September 3rd, 2006
