I started making soap not too long ago (December), so I started saving my waste fat to make more soap. I recently pulled out all those trimmings from the freezer so that I could render them. Rendering is the process of separating the fat oils from the meat and gristle. So I thought I would share the process if anyone is interested in rendering their own fat for candles, soap, lotions, etc. etc.
Step 1: Cut or chop the trimmings into little bits. A food processor helps with this or you can even use your blender. If using the blender only work with very small portions as it really overworks the motor. The smaller the pieces the easier the fat separates out in cooking.
Step 2: Put your chopped up trimmings in a pot that is big enough so that the trimmings only take up half the pot.
Step 3: Place about 2-3 inches of water in the pot.
Step 4: Bring the trimmings to a low rolling boil and keep them there for about 30-45 minutes. Keep the boil low enough so that the fat is cooked out but nothing tries to scorch or stick to the pan.
Step 5: Line a strainer with cheesecloth and pour the boiled trimmings though into a mold. I used a couple loaf pans for a mold. Let the fat cool, then place in the refrigerator overnight. The fat will rise to the top and harden somewhat. Now if you have any leftover liquid it will settle on the bottom. You can either choose to skim off the fat at this point or do what I did with the second loaf pan. I put it in the freezer, then when frozen i removed the whole loaf and simple cut the non fat (mine was gelatin) off of the fat layer. The fat layer will be solid white.
Step 6: Store your fat in the freezer for future use or use immediately.
Now the brown meaty bits that you have left after rendering is called suet. I feed it to the chickens. Dogs, cats, pigs love it too. I suppose you could make a suet type cake with peanut butter or such to hold it together and put it out for the wild birds. I just put mine in a large container in the fridge and each day add a good couple spoonfuls to the chicken bucket. They love it and it is a great source of protein and calories. The gelatin that I cut off the fat after molding was fed to the dogs. I used about half of the fat to make some laundry soap. Because the fat was tallow (beef fat) and lard (pig fat) mostly with just a smattering of other waste fat the soap turned out pretty crumbly. Of course, I might have done something wrong in the processing. However, even though it crumbled into little bits it definitely is soapy, and little crumbly bits are great for laundry since I don't have to grate the bars now. Anyway, I washed my first load of laundry yesterday with my new soap and it turned out just fine. So, don't waste those fat trimmings. They are a valuable resource for the home. Blessings, Kat