Soap and Lye

I have been saving leftover fat for almost a year now. I have two containers in the freezer -- one filled with bacon grease that I use for cooking and another filled with "other fats" that aren't very tasty. My goal? To make soap.

To make soap you need three things: fat, water and lye. You combine them and stir over heat for about an hour before pouring the thickened "pudding" into wax paper-lined trays. Recipes for it are all over the internet. Lye is the hardest of the materials to find. It used to be very easy to find -- it was used as a drain cleaner and found at any hardware store. It could be added directly to your soap before companies started adding lots of metals to their cleaners, making them unusable for soap production. Then lye was found to be a major component in the production of methamphetamine, which made finding it a lot harder due to state regulations. It's no longer in the hardware stores in Oregon. Now it is also being used in the production of biodiesel, so the price is a lot higher than it used to be a few years ago. I found mine online and bought 9 lbs (the smallest increment I could find) for $22. A friend is taking some too. The most amazing part is the store is closed on the weekend, but the owner allowed me to pick it up from his house on the Saturday. Pretty nice of him.

Anyway, I cleaned all my fat on Friday night (which may explain why we only had 6 trick or treaters). I weighed it and put it in the fridge. 3 lbs of random fat, including bacon grease, chicken fat skimmed from stock, even the leftover bacon fat that I used to infuse some bourbon with this summer (you add bacon grease directly to the bourbon, let it cool on the counter then throw it in the freezer to solidify and pull off the fat). I threw that leftover fat into my soap collecting container too.

On Saturday, I heated two containers to 100 degrees F. One of fat. One of lye. When they were about a degree apart, I added the lye to the fat and stirred for an hour over a double boiler. You could see everything thickening up.

My molds were simple metal pans lined in wax paper. I poured my pure lard soup in one of the containers. In the other, I mixed some wheat germ as an exfoliant, then poured that batch into another mold. I covered both with plastic wrap and insulated them with a towel before cutting into bars the next morning. They were still somewhat warm. I now have about 15 bars of soap total. The lard one is a pure white, just like the picture (which isn't of my soap, although it looks identical). Not bad for free, leftover, icky fat.

I'm going to let the bars cure for a few weeks before testing them out, but they look good so far. Plus, they were the easiest pots to clean since they were already filled with soap. You could see the bubbles when you added the water to clean them. I love self-cleaning projects.

So, save your fat for me. Or borrow some lye. Making soap is way too easy to not do again.