2.5 gallon BIAB with 4 gallon kettle

[CrixusOfCapua]

Can I do a 2.5g batch of BIAB with a max 4 gallon kettle? I want to mash in what water I can get in the kettle, do the sparge and boil process then dump water in the fermenter to bring up to 2.5g. Is that going to throw the numbers off or affect the beer?

 

[wilserbrewer]

You can certainly do a 2.5 gallon BAIB batch in your 4 gallon kettle. Depending on how strong a beer your making, a sparge may be needed. If you start with as large a volume as possible, and keep your boil off reasonable you shouldn't need to top off the kettle with water.

 

[jekeane]

I use a 3.7g kettle and do full volume 2 gallon batches on 1.055 and below beers 2.5g batch size would be cutting it super close I assume. you could do a pour over sparge to get pre boill volumes but i would definitely use fermcap s (defoamer) pre boil to avoid a mess.

the biabacus spreadsheet for biab recipe formulation has column for calculating top up water. I have never used them personally but I would assume they work well allowing you to top up.

 

[pricelessbrewing]

You'll be limited to about 1.07 without a sparge, ~6.5 lb. Beyond that you'll need to either do a sparge, top off (will take a hit for your efficiency), or use extract to get you the rest of the way.

 

[CrixusOfCapua]

So im guessing its impossible to do with a 2.5g kettle then. Looked last night and I guess I had it wrong.

 

[chask31]

I have done it with the $12 4 gallon Walmart kettle. I have since moved on to another system but did about 10 batches. Totally doable and produced good beer. I sparged by putting the bag into a separate 3 gallon pot at 170 degrees.

 

[Culln5]

Yup, I do that exact thing for my small batches and test batches! I typically use 1 gallon of fermentor "Top Up" water. Occasionally, for high gravity brews, I will need to also hold back mash water due to space and then add it to the boil.