This is the time of year that many of us fill up our freezers. For a soap-maker, this is also an opportunity to get a key ingredient for a bar full of lather. Augustus Ranch has a website that teaches how to render pork or beef fat. Rendering makes it shelf stable by removing the moisture. They suggest using the fat harvested from the kidney or organ areas. Below are instructions.
Start with the raw pork (left) and beef (right) fat. Put a small amount of water at the bottom of the pot you are using to render the fat (around 1/4th of an inch). Just enough to cover the bottom. This prevents the fat from browning as we begin to heat it up. Turn the pot on a medium low heat and let the fat gently warm up and begin to liquify. The fat pictured here was ground once, but you can also dice it up with a knife by hand into smaller bits for easier rendering.
Gently simmer the fat. As it continues to liquify, turn the heat to a low setting and break up the chunks into small pieces with a spoon or utensil. They will eventually become tiny bits. The slower, more gentle we render the fat, the more neutral it will be. If the temperature and heat gets above a certain point, the fat will begin to brown and caramelize. This isn't necessarily a bad thing, but we're going for a pure, neutral fat base. You should see some steam coming off the fat, which is exactly what we want. We want to evaporate the water to create a more shelf stable product. Stir it occasionally and keep it simmering on a low heat.
Finish rendering. After about 20 minutes of simmering (for one pound of raw fat in this recipe), the water should be about done evaporating. The liquid fat will turn clear and no longer have a cloudy appearance. This is how we know it's done. Turn off the heat and let it cool on the stovetop before final handling. It's obviously going to be very hot. I recommend letting it rest for a minimum of 20 minutes.
Strain and store. Once the hot fat has cooled down a bit (it will still be hot), take a fine mesh strainer and empty into your desired storage vessel. I'm using a glass jar because it's not going into the freezer at any point. If I did want to store in the freezer, I would use a plastic quart or pint container, leaving some space at the top. That's it! You've got rendered fat which can now be stored at room temperature, or better yet, in the refrigerator where it will last virtually forever. Let it cool down completely at room temperature and do not cover it until completely cool. Covering it while hot may create steam which will result in the formation of water (which is what we want to eliminate).