Tallow 1 (beef fat)

My local market advertises "hand trimmed meat", so I asked the butcher if I could have some of the trimmings. He was happy to oblige, for no charge! I got 40 oz of mixed trimmings.

I estimate the composition at about 40% hard fat, 50% soft fat, 10% connective stuff.

• I chopped it as best I could into cubes between 1cm and 1in in size. The connective tissue I just tossed in straight.
• I added 60oz of water to the fat, and boiled it (low boil) for several hours. Suprisingly, it didn't make much of a change in the fat.
• I set it aside for the evening
• I boiled it more vigorously for 2 hrs in the morning, and it clearly began to separate.
• I kept a little water in the bottom of the pot the whole time, but it boiled away rapidly, so I was replacing it fairly frequently.
• After another 2 hrs, the fats seemed to be mostly dissolved.
• I set it inside a sink with cool water, and once it was cool, I put it in the fridge overnight.
• The next morning I broke the tallow cake and emptied out the water underneath, which was crowded and clouded with various material
• I cleaned the pot, put in some more water, tossed the tallow chunks back in, and repeated
• The tallow came out cleaner the second time, as did the water
• A third pass was yet better

I've become convinced that a little judicious scraping of the water-side of the tallow cake does a lot to improve the purity of the next iteration of the cake.

First rendering

Second rendering

A light scrape after the 3rd render made the 4th one dramatically whiter.

Results
* MATERIALS 40 oz beef trimmings, 2-4 gallons of water.
* PROCESS I did 4 renderings, including the initial one.
* PRODUCT The tallow stayed soft at any temperature above refrigerator temps (40 deg F) which is a bit of a bummer.
* YIELD I ended up with 19.5oz of tallow from my initial 40oz "beef trimmings" sample. Not sure if that's good, bad, or typical.