Yes, it goes without saying that one who handles lye must know just how powerful it is - the best way to do this is to imagine that you are handling concentrated sulphuric acid (and lye DOES fume as it is mixed with water).
AP: It is hard to post a recipe as soapmaking is closer to chemical synth than it is to cooking.
Very roughly, the absolute simplest soap can go something like this:
20lb Olive Oil
2.6lb NAOH
7.5lb Water
- The lye-solution is prepared by slowly pouring the lye into the water (and not the other way around) while stirring. Goggles and gloves are a must. It will go very hot and start fuming...
- The oil is heated (in a non-aluminum, non-teflon pan), some people suggest to bring it up to the same heat as the lye, but I find this unncessary.
- The lye-soln. is carefully poured onto the oil while stirring vigorously.
- Mixture will go through several phases, must be continuously mixed and stirred, until it reaches pudding-like consistency (it should be opaque too). This is the trickiest part, as it can take anywhere from 10secs to 1hr (although with olive oil it almost always takes a long while).
- From here many methods differ, the easiest being to turn down the heat and pour this stuff into a mold. From there, if given enough time (=weeks) it will self-propel its own reaction and eventually harden. You can test if it is finished by placing it near the tip of your tongue - if it "zaps" you then it is still not ready.
The subject is surprisingly deep and complicated, and the above is an extremely rudimentary guideline.
I've been tinkering with it the past year or so and have finally settled on a soap that contains no less than 7 different oils in different proportions, the stars being olive and avocado oils. The latter is amazing for skin, being particularly rich in vitamin E amongst other things.
Curiously, the method is almost identical to making biodiesel from clean, unused oil, with the exception that biodiesel requires the lye to be mixed with methanol first.
