Few people know that most of the soaps and shampoos they use are actually detergents (and thus petroleum based). The minerals in water differs significantly across the country, which means that different types of soap work better in different places. For the longest time, this meant that regional soaps really
were better than national ones. Once chemists figured out how to create super-powered petroleum-based detergents, though, companies were able to brute force the differences and sell one thing across the entire country.
Not only does this mean that our cleanliness is now closely connected to our petroleum dependence, but it's bad for the water (and maybe even our health). Luckily, making local soap is pretty easy, albeit time-consuming. I recommend getting some folks together and hosting a soap-making party one afternoon, since there's a lot of stirring. To keep the stirring theme going, you could also make ice-cream by hand.
But back to soap. You'll need to set aside some common household implements for soap use. Once they've touched lye, you're not going to want to use them to cook anything else.
You'll need:
- a stainless-steel pot
- a stainless-steel stirring spoon with a long handle
- a tub or mold (this'll determine the shape of your soap, so try to get something without ridges)
- a serrated cutting knife
- gloves and goggles! Lye is bad stuff, so don't mess around
- a bowl for lye
- two candy thermometers
Apart from the hardware, you're going to need water, lye, and oil/fat. The lye you can get at most hardware stores in the drain cleaner aisle. It comes in little bottles kind of like aspirin. For "fat," I recommend starting with olive oil. Okay, so it's technically not without oil, but it's still
sans petroleum :). You can use other vegetable oils, but usually in mixture with other things. You can also use different types of animal fat, but then you have to render it out. It's easier just to use vegetable oil, so that's what we'll do.
Different soap recipes call for differing amounts of fat, water, and lye, but here's a simple one:
- 12 ounces of olive oil
- 2.1 ounces of lye
- 6 ounces of water
You can scale the recipe up, but I wouldn't try scaling it down. If you have exceptionally hard water, you can try increasing the amount of lye a little as well. Eventually, you'll hit on a ratio of lye to fat that works well for your area.
Now for the stirring party! Well... almost. First, carefully mix the lye and water by pouring the lye into the water. Set it aside with a thermometer in it. It should be pretty hot at this point (~120-130F)! Now, heat your oil up to about 110F in the pot. Check to see if the lye/water mixture has cooled to 110F yet. If not, you can put the bowl in a sink with cold water and ice cubes in it.
Once the two mixtures are both within 5 degrees of 110F, carefully add the lye mixture to the oil. This will start the saponification (soap-making) process. Take the pot outside and start stirring!
This part takes a while (45 minutes to an hour, depending on the type of oil used). You're looking for what soapies call 'trace'. Basically, this means that your mixture has attained the consistency of a thin pudding. If you pull your spoon out of the mixture and it slowly drizzles back down, you're there.
Once you've got trace, you can pour your soap into the tub (or molds if you got fancy). Set them aside to solidify, which takes 3-5 days.
After they're solid, pop out the blocks and cut into appropriately-sized squares. It should look like soap at this point, but be careful! There might still be a little lye left behind. The saponification process isn't complete either. You'll need to set the squares aside for 4-6 weeks to finish drying. If you just used olive oil, you can probably get away with drying them for a little less time.
To test out your soap, just chip off a piece and try using it! If it tingles a lot or burns a little, there's still too much lye in it and it needs to dry out more. If it tingles a little or not at all, you've got your own soap!
If you're feeling fancy, you can melt it down at this point and add colors and scents and pour it into molds. It only takes a day or two to re-solidify so you don't lose much time in the process.
It's not worth it to make tiny batches of soap (and gets harder if you get a recipe much smaller), so I recommend trading it with other people. Maybe you can get some candles or fresh produce from a neighbor!
Happy cleaning!