Double ipa BIAB

question? I have a 5 gal cooler that I use as a mash tun for doing BIAB or 2.5 gal AG batches. I want to do a couple bigger beers, but the grain bill will not fit into the cooler. Im wondering if i can mash half the grain, collect the wort in the kettle…then mash the rest of the grain and combine the 2 and proceed as usual??

Any problem with holding onto the 1st bit of wort while the other stuff mashes???

I know i could invest in bigger cooler etc…but im looking to do this with the stuff I got now.


Are you wanting a higher OG?

There is a process called “reiterated mashing”. Where you mash 1/2 your grains and do a normal run off. With extra wort collected to account for absorption of the 2nd 1/2 of grain. Then, mash the 2nd 1/2 of the grain with the “wort” from the 1st mash.

I have done this and it works well.

Or are you wanting to have a larger volume?

You can mash 1/2 the grain and sparge normally for that volume. Say 3 gallons. Then mash the 2nd 1/2 of the grain and sparge normally for the same volume. Ending up with 6 gallons preboil and 5 gallons at the end of the boil.

With this, I would bring the 1st sparge up to a quick boil to reduce the possibility of the wort souring while waiting for the 2nd sparge. Not likely to happen, but easy to avoid.

I want a higher OG…I would like to make a 3gal BIAB DIPA and RIS.

With my 5 gal Cooler there just isnt enough room for water and grain

The reiterated mash should work for you. Mash the 1/2 the grain and end up with a bit more wort than normal, to account for the grain absorption on the 2nd mash.

Heat the wort back up and mash the 2nd 1/2 of the grain.

Up the grain bill a little to account for a reduced efficiency of 5-10%. If you end with a higher OG than expected you can always add some water.

Or you can mash with the max you can and augment with some DME.

I typically do 3 gallon BIAB batches in a 5-gallon cooler. When I want to brew high-gravity batches I either A) Make do with a smaller batch size or B) Batch Sparge.

I am planning on trying a super huge barleywine at some point where I pull my grains out and do a second mash using the first runnings as my brewing liquor, but it will be a while before I get to that.

For an OG of 1.104 (at 60% efficiency), you could mash 12 lbs of grain with three gallons for a total MT volume of 4.5 gallons, then sparge with another two gallons and get 3.5 gallons in the kettle.