Biab Crossover

[jimmysuperlative]

I've been Brewing in a Bag BIAB (linky) for a while now ...and enjoying the results immensly!
However, I'm looking to maximise my output and "double batch" ...to produce around 45L of wort.

I already have a 55L vessel, which I use for my single batch BIAB, and I'm about to purchase a 120L vessel to upgrademy system.

What I want to know is if my "grain bag" (which completely lines the 55L vessel) could be used as the false bottom of I make the 55L my mash tun?

The "bag" is made from fine nylon voille (cutain material) and allows no grain/husks/bits to escape to the wort.
I'd be batch sparging, BTW.

So ....what do you reckon? I'll probably give it a go anyway, but, I'd like the "experts" opinion.

 

[jimmysuperlative]

Bump ... :mellow:

 

[Wardhog]

I'm about to do something similar, in that I have a voille bag (triple stitched, stress tested to 15kg) that the grain will sit in while I mash. Once the mash has finished, I'll lift the bag out of the mash tun, empty the mash tun into the kettle, put the grain bag back in, and add an amount of sparge water.

Example:

mash.
Grain in bag (4.5kg) sits in 12L 66C water for 90 minutes.
Remove bag o' grain
Tip ~7L sweet wort into kettle.

sparge 1.
Grain in bag (4.5kg + ~5L trapped water) back into empty mash tun
Add 12L 75C water to mash tun with bag in it, sit/stir for 15 minutes
Remove bag o' grain
Tip 12L sweet wort into kettle

sparge 2.
Grain in bag (4.5kg + ~5L trapped water) back into empty mash tun
Add 12L 75C water to mash tun with bag in it, sit/stir for 15 minutes
Remove bag o' grain
Tip 12L sweet wort into kettle.

bag o' grain reaches end-of-life, to the bin with it.

Total of 31L sweet wort in kettle. I've done this successfully on a smaller scale (2kg grain for 13L ~1.040 wort),
Is this what you mean? Or have I misunderstood?

 

[jimmysuperlative]

I'm about to do something similar, in that I have a voille bag (triple stitched, stress tested to 15kg) that the grain will sit in while I mash. Once the mash has finished, I'll lift the bag out of the mash tun, empty the mash tun into the kettle, put the grain bag back in, and add an amount of sparge water.

Example:

mash.
Grain in bag (4.5kg) sits in 12L 66C water for 90 minutes.
Remove bag o' grain
Tip ~7L sweet wort into kettle.

sparge 1.
Grain in bag (4.5kg + ~5L trapped water) back into empty mash tun
Add 12L 75C water to mash tun with bag in it, sit/stir for 15 minutes
Remove bag o' grain
Tip 12L sweet wort into kettle

sparge 2.
Grain in bag (4.5kg + ~5L trapped water) back into empty mash tun
Add 12L 75C water to mash tun with bag in it, sit/stir for 15 minutes
Remove bag o' grain
Tip 12L sweet wort into kettle.

bag o' grain reaches end-of-life, to the bin with it.

Total of 31L sweet wort in kettle. I've done this successfully on a smaller scale (2kg grain for 13L ~1.040 wort),
Is this what you mean? Or have I misunderstood?

At the moment I use the 55L vessel as mash tun and boiler ...I fill the pot to 38L, secure bag, pour in grain according to recipe (4-5kg), heat water/grain while stirring to mash temp, cover with lid and leave for 60-90 minutes ...then, remove bag of grain to drain and collect 4-6L in bucket, return this to the rest of the wort to give 32-34L which reduces to around 26L during the boil. I lose a couple of litres to "break" material, and normally get around 23L into the fermenter.

What I want to do is closer to a more traditional AG. ie heat mash water, add to insulated pot with grain contained in voille bag ...drain pot (through voille bag) and collect wort in a larger vessel, batch sparge to collect total of 50-something litres. Reduce to 45L with boil.

I really want to know if anyone can see any problems with using the bag this way? I suppose a similar result could be achieved by dubling the grain bill and adding top up water for the boil?

I'm trying to avoid the "lifting" of 16-18kg of wet grain if I'm double batching. Does this make sense?

 

[Wardhog]

What I want to do is closer to a more traditional AG. ie heat mash water, add to insulated pot with grain contained in voille bag ...drain pot (through voille bag) and collect wort in a larger vessel

So, you have a tap in the bottom of your 55L vessel? I can't see why this wouldn't work - but keep in mind I haven't even done my first full batch AG (I'll lose my virginity tonight), so take my opinion at your own risk.

Out of interest in the BIAB method, how much effort is required to keep the contents of an SS vessel at a certain temperature for 90 minutes? Do you have to turn the heat on every 10 minutes or so?
I have a 50L converted keg that I'm going to use as a kettle, just wondering how hard it would be to use as a mash tun.

 

[jimmysuperlative]

So, you have a tap in the bottom of your 55L vessel? I can't see why this wouldn't work - but keep in mind I haven't even done my first full batch AG (I'll lose my virginity tonight), so take my opinion at your own risk.

Out of interest in the BIAB method, how much effort is required to keep the contents of an SS vessel at a certain temperature for 90 minutes? Do you have to turn the heat on every 10 minutes or so?
I have a 50L converted keg that I'm going to use as a kettle, just wondering how hard it would be to use as a mash tun.

Good luck with your first ag ...hope its a smooooth brew for you!

I've been doing a bit of reading, and found some great on-line resources about using mash/sparge bags ...like this one mash/sparging bag posted by Dan A yesterday (thanks Dan!) ...I pretty sure it will all be good!

My vessel is an aluminium stockpot which is both mash tun and boiler (using the BIAB method). With 38L of water and grain added and heated to mash temp, I lose about 3-4 degrees over a 90 minute mash. I check temps during the mash every 30 mins and add heat by giving a 1 - 2 minute burst with my burner.
I could wrap the pot in some insulating material to improve the efficiency.