How can I efficiently render 100 lbs of suet into tallow in a home kitchen? As I mentioned in another question, I'm about to undergo a 100 lb suet-to-tallow rendering process.  The problem is, as much as I love tallow, I've never rendered suet myself before and I have a million questions (though I'll try to keep it to a few key points).  After a lot of research, here is what I've come up with:


Trim, chop, and partially freeze suet
Run it through a food processor
Render with or without water
Strain and cool


It seems there are 3 rendering options for the typical home kitchen:


Oven at 250°F
Stovetop on low/very low (I have an electric range/hobs)
Crockpot on low setting


And then there's a difference between rendering the fat by itself, or rendering it in water.  A few convincing articles imply that rendering it in water creates more "pure" tallow.

I figure since I have so much to render, I'll try all three methods above simultaneously.  I have: two crockpots; an enameled cast iron dutch oven and a few large stock pots for the stovetop; and a lot of casserole dishes for my two-rack oven.  Even doing them all at the same time like this, I imagine it's still going to take a few (many?) rounds to render it all.  I'd like to minimize that time if possible since I don't have room to store the suet for long, but producing quality tallow is equally important as I'll be giving some away.

My questions:


Are there any methods for doing this in a typical home kitchen that I'm missing?  The grill, perhaps, or is that too dangerous?  I also have an electric wok.
How can I do this as efficiently and quickly as possible?  For example, can I stack casserole dishes in the oven or do I need to keep air flow maximized and just do what fits on the two racks at a time?  How hot can I have the oven and stovetop without risking quality loss?
Should I render with water or without it?  Will it really make it more pure if I use water, and if not what will?
About how much tallow can I expect to get from 100 lbs of suet?  I have a rough estimate of 20 gallons in my head but that's based on numbers I found from a Google search.
It depends on what you need the tallow for and whether you want it to taste significantly of beef or not, water rendering will give a cleaner tallow.

With 100lbs of tallow, your main limiting factor is driving off all the water. Tallow is about 75% fat, 22% water and 3% protein so you basically need to boil off 22 pints of water. What heat sources do you have that's going to most efficiently boil off 22 pints of water?

Here's what I would recommend: chop about 1 - 2 lbs of the tallow into 1/2 inch sized pieces to start off with and start them rendering in a pan on the biggest burner you have set as high as possible. Place a thermometer in there and monitor when it reaches 250F, making sure to keep the bottom of the pot scrupulously clean of stuck on bits (if there are stuck on bits, transfer to another pot so that the bottom stays clean).

When it reaches 250F, add in another batch of tallow pieces too cool down the pot and wait until it gets back up to temp again. Repeat until all the tallow is rendered.

This process can be parallelized with multiple pots and thermometers if so desired. The more heat you can apply, the faster this will go.