I do only 2.5 gal size batches. All BIAB. I have done about 20 of them. I use a 16 quart (4 gal) aluminum IMUSA pot. It is easy to store, heats and cools fast, fits nicely on a burner, and I can use it for other things. Lobster, corn, etc. Usually I have to top off the keg with some water...