Tallow is one of the best fats to cook with. In the olden days, it was easily available, but thanks to the low fat maffia, I can't find it in supermarkets anymore. Big bummer, but I know my way around a kitchen, so I decided to make the stuff myself.
My butcher is totally awesome. Besides being a qualified butcher, with an amazing range in all sorts of meat, he's also a farmer. When I asked him what he gave his cows to eat, he said "Eh..well, grass!". He said it in way as if it was the most normal thing to do, and that I was nuts for thinking that cows could actually eat something else. Gotta love the guy!
He provided me with an enormous piece of suet. For free, because he usually throws it away, because no one wants it anymore! I rendered it using this site as a guidance. I chopped the suet into cubes, put it in a food processor to crumble. I didn't bother with freezing the crumbs and had no problems.I had to do it in three batches, because I had so much suet. I just dumped the suet crumbs in a big pot (I chose the "dry stove top method"), put it on very low heat, stirred once in while and when all was liquid, strained it through a very fine sieve (cheese cloth would be perfect too).
It was a little messy (my hands and work surface felt like they where covered in candle wax), but two hours of chopping and melting, left me with three big jars of tallow. I can probably cook for 2-3 months with that. So to me, that's worth the effort!