I render fats and oils for various purposes, so I thought I would share with you the basic method I use to do it. I am sure it is age old, and it gives a product that will last hundreds of years if you keep it cool and sealed from the air. If you have never rendered before, I suggest getting about 5lbs of tallow from the butcher. You want the hard crumbly white tallow, not the fleshy white stuff. You especially don't want to use fat attached to flesh since it is extremely difficult to render pure. Instructions: - Move everything OUTSIDE! Don't even consider doing this in the kitchen - Cut the tallow into small pieces - Simmer tallow in a large skillet until the pieces shrink and turn a medium brown. Don't burn the cracklin's - Place strainer over large crockpot or other large pot - Lay several layers of cheesecloth, pillow ticking or other fine mesh cloth over the strainer as a filter bed - Poor the liquid fat through the cloth and strainer - Add water to the pot such that you have at least 4 times as much water as fat. More water is better. - Boil for 4hrs with lid on to dissolve out salts and other unwanted stuff, and maintain water level - Watch for coagulation of proteins, or early whitening of water. You might want to do the previous step twice with a fresh water change if you think it is necessary - Set pot in frig until fat has hardened. Drain water - Add fresh water again and bring pot to boil - Filter once more into an auxilary vessel if you see coagulants - Set pot in fridge until fat has hardened - Drain water, remove hard fat - Clean pot, then slowly simmer fat in pot until all water has been lost and pot falls silent - Pour liquid fat into clean jars with lids, then place them in freezer for later preparation You can use the tallow and its derivatives for everything from food preparation and food preservation, to lubrication, corrosion protection, and leather treatment. There are a million uses if you know what to blend with it. Good luck.