BIAB Capacity issue for big beer

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teamrushpntball

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So have an idea to do a batch larger than my mashing capabilities. Any guesses if my idea will work?

I know I can only hold around 18lbs of grain in my 10 gallon BIAB setup to make a 5 gallon batch.

I want to do a 6 gallon batch, using around 24 lbs of grain.

My thought is to do two separate mashes then combine back into a single boil, hopefully ending up with 7 gallons of wort (6ish after trub loss).

I'd split my grain in half, do the first mash and drain into a holding vessel. Do the second and combine the two back into my kettle for the boil. Any flaws with my plan, or suggestions to improve?
 

TheMadKing

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So have an idea to do a batch larger than my mashing capabilities. Any guesses if my idea will work?

I know I can only hold around 18lbs of grain in my 10 gallon BIAB setup to make a 5 gallon batch.

I want to do a 6 gallon batch, using around 24 lbs of grain.

My thought is to do two separate mashes then combine back into a single boil, hopefully ending up with 7 gallons of wort (6ish after trub loss).

I'd split my grain in half, do the first mash and drain into a holding vessel. Do the second and combine the two back into my kettle for the boil. Any flaws with my plan, or suggestions to improve?
That should work just fine. I've done that with a barleywine and it worked pretty well. It might be a good idea to do a mash-out, otherwise conversion will continue in the holding vessel during your second mash.

Another bonus is that it will increase your mash efficiency slightly as well, which is always an issue for large grain bills.
 
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teamrushpntball

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I normally mash-out at 165-170 for ten minutes before firing backup to go to my boil. Would that be sufficient?

I'm thinking 12lbs of grain and 5.4 gal water for each half. Planning a 12ish Imperial Stout and letting it age until Christmas.
 

TheMadKing

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I normally mash-out at 165-170 for ten minutes before firing backup to go to my boil. Would that be sufficient?

I'm thinking 12lbs of grain and 5.4 gal water for each half. Planning a 12ish Imperial Stout and letting it age until Christmas.
Yep that'll be perfect. Good luck! Just be prepared for your brew day to be SNAFU, something always goes slightly wrong when you deviate from your routine.
 

doug293cz

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That should work just fine. I've done that with a barleywine and it worked pretty well. It might be a good idea to do a mash-out, otherwise conversion will continue in the holding vessel during your second mash.

Another bonus is that it will increase your mash efficiency slightly as well, which is always an issue for large grain bills.
Actually two mashes, each with half the grain and half the water of a larger mash will have the same mash efficiency as the larger mash (assuming you get the same conversion efficiency in all the mashes.)

Brew on :mug:
 

doug293cz

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I normally mash-out at 165-170 for ten minutes before firing backup to go to my boil. Would that be sufficient?

I'm thinking 12lbs of grain and 5.4 gal water for each half. Planning a 12ish Imperial Stout and letting it age until Christmas.
At 0.08 gal/lb grain absorption, 12 lbs in 5.4 gal will give you 4.44 gal pre-boil at an SG of 1.069 and 72% mash efficiency (both assume 100% conversion efficiency.) If conversion efficiency is less, then SG and mash efficiency will be proportionately less. If you boil that down to 3.0 gal (6 gal total) then your OG would be about 1.102. If boiled down to 2.75 gal (5.5 gal total), OG becomes 1.112.

Brew on :mug:
 

aamcle

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Reiterating mashing might interest you, you would need to Google it.


aamcle
 

ong

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When I'm trying to do a bigger beer than my BIAB setup can handle, sometimes I'll just treat as partial mash and add a few lbs of extract to make up the OG and volume I'm targeting. I've done both high OG 5 gallon batches and normal 10 gallon batches that way.
 

TheMadKing

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Actually two mashes, each with half the grain and half the water of a larger mash will have the same mash efficiency as the larger mash (assuming you get the same conversion efficiency in all the mashes.)



Brew on :mug:

I've found that the grain absorption for a larger mash is higher because it's more difficult to squeeze all the wort out of a larger mass of grain hanging in a bag, so the lauter efficiency is somewhat lower. This may simply be a product of my process/impatience though.

But you did make me remember that I increased my water volumes slightly and did a 120 minute boil. Sorry OP I forgot that part!
 
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teamrushpntball

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Reiterating mashing might interest you, you would need to Google it.


aamcle
I looked this up yesterday evening. Seems to just be an improvement on my idea. I simply use my wort from the first half as my liquid for my second half of the mash. It looks as though I need to adjust mash temps, but seems like a slightly easier way.
 

doug293cz

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I've found that the grain absorption for a larger mash is higher because it's more difficult to squeeze all the wort out of a larger mass of grain hanging in a bag, so the lauter efficiency is somewhat lower. This may simply be a product of my process/impatience though.

But you did make me remember that I increased my water volumes slightly and did a 120 minute boil. Sorry OP I forgot that part!
Yes, I should have noted that the equal efficiencies for two smaller vs. one larger mash (with same grain to water ratio) assumes the same grain absorption rates for the small and large mashes. Higher grain absorption rates lead to lower efficiency, as do higher grain to water ratios (more water increases efficiency.)

Brew on :mug:
 

doug293cz

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I meant mash all the grains at once but with 60% :))) of the water. Then batch sparge with the rest of the water, since it wont all fit. Am I off here?
No, that's a good plan. I just couldn't get that from your earlier post. It was the "all at once" that threw me, since mash and sparge have to be separate (sequential) operations.

Brew on :mug:
 
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