BIAB 2.5 Gallon Batches - Brew Pot Size

[BlakeL]

I did a boil test yesterday and it was pretty hard to get a consistent flame because of the wind. It took about 20-25m to bring 4 gallons to boil. The bottom of the pot had some dark ash from the flame and some paint that melted from the metal. I think it will take a few more boils to get my full impression and hopefully it won't be so windy when I brew my first BIAB batch in a few weeks.

 

[El Nino]

A 5-6 gallon stock pot should suit your needs fine. Keep in mind that minimal empty space in the pot means better temperature retention during the mash.

This, and it's pretty huge. I mashed a 2.5 (ended up being almost 3) gallon batch in a 5 gallon pot, and it was a perfect fit (target OG was 1.069 with a 6.75lb grain bill). It was filled nearly to the brim with the grains in there, but I didn't even need to insulate / cover the pot during the mash. After 1 hour, the temperature only changed by 1 degree. If you have a pot with minimal empty space, you don't need to bother with covering the pot with insulation.

edit: Just noticed you were doing the brewing outside, that might change things. What I said applies to stovetop brewing with a 75 degree room temp. If it's cold outside that might change things.