Love this thread!
Being a fat lover (yeah, I know, but don't care) I rendered lard all my life,still do.
When it comes to leaf lard,used to bake with it a lot. Not anymore, because I can't find it here!
Now ,I have to say though, we never render leaf lard for baking. Clean it, scrape it off the membranes and knead with a little flour. Then use as you would use butter in puff pastry.
I have different recipes for this (for different sweets), but this is the basic in all of them.
Rendering lard from back fat, I do it differently.
Big, heavy pot, lots of fat pieces (not one layer) cut into 1" cubes. Heat them up, stirring, so all the pieces get warm and kinda translucent, then pour some milk over them. The amount of milk depends on the amount of fat of course. I usually do at least 4 lbs at a time and the milk would be about 2 c.
Now you can leave them alone over moderate heat, stir every now and then.
Start tending to it when the fat becomes clear looking. Stir often and don't let the bits turn too dark. Keep taking them out into a bowl with a slotted spoon. It happens fast at this point. If the liquid fat seems to get to hot, turn off the heat. The pieces will still cook further.
Once they are all out ,sprinkle them with a bit of cold water and cover immediately.
The steam does wonders, all those little golden pieces will be crisp on the outside and soft and wonderful on the inside.Salt them while still hot.They are absolutely wonderfuk to munch on with a piece of good bread, some pickles or tomatoes, or chiles, or all of those.
Oh let's not forget about the lard!
While the little pieces (what are they called? Not cracklings I think, those are from the skin, right?) are having their sauna, strain the lard through a fine sieve into a tall, preferably metal (or crock) container with a lid.
There will be some left over in the pot with bits and pieces in it.
Keep it! You can use that for baking too.
Now, I just know I wrote this all down here before, didn't I?