We would like to start working our way up in batch sizes, as well as plan on ordering much larger equipment. What are your recommendations for yeast pitching for larger volumes? How would you go from 50 gallon to several hundred or even a 1000 gallon? Seems like handling starters or multi-stage would get more difficult, but yeast becomes a real expense at that point. We have a few 5L flasks we are using now.
Are you talking about propagating from slants?
No, not starting from scratch with a slant, but using commercial quantities, say 500g, to make a large starter, then build up, versus buying a 1000g or 2000g...etc. Very little documentation out there on mash size greater than 50-100gal.
10x rule for yeast prop. If you are pitching into 1000g, you'll need a 100g ferment as the prior step. Something like a small 3bbl conical. Continuing that, you'll need a 10g tank as the step before the 100g. It's relatively easy to convert a 1/2bbl keg into a prop tank. You'll need to do the math to determine the cost of the time, effort, and fermentables necessary to jump from 10g to 1000g. You may need multiple tanks depending on how many fermentations you might run during the week. Heck, if you've gone this far, you can start in your 5l with an even smaller volume.
Worth noting, if you are fermenting lautered beer, every fermentation is a yeast propagation opportunity. You can go 7 generations. Even if you are focused on corn-based products, consider doing lautered malt whiskies simply for yeast propagation purposes. A single 1000g ferment will give you 10 1000g pitches. You basically get the whiskey for free at that point.