Unless you are using a CFC, don't forget to leave room for your immersion chiller. Batches that big need a large one and they take up a lot of volume.
We use
this pot for 20 gallon batches. It's about 33 gallons and its just enough since we leave
our chiller sitting in the pot in for the entire boil and our pre-boil volume is a little high (around 25 gallons) because:
- We want about 5.25 gallons for each primary bucket (21 gal)
- We lose about a gallon in the trub due the big flat bottom of the pot (22 gal)
- We lose about 3 gallons to boil-off (25 gal)
With all this, the pot is *just* big enough for a 20 gallon batch. With a CFC instead of the chiller in the pot, we could do 25 gallons no problem.
Hope this info helps and good luck!
P.S. We use an old Bayou Classic burner and it works fine. However, we had to build a stand for the pot out of cinder blocks as almost any burner stand will be too weak to hold that weight.
P.P.S. You may already have this worked out, but there are a host of other issues with doing large batches. For example, heating your 30+ gallons of strike and sparge water and the fact that your (huge) mash tun is now too heavy to move once it's full. If you want to chat, PM me your number and I'll be happy to relate to you every disaster we encountered moving to large batches.