Double Batch Biab Mash Vol?

[BeauVinnie]

Hey anyone found a good BIAB mash volume for a 45-50L (in fermenter) batch, ie double batch? I have a 70L pot

 

[katzke]

Double batch is double batch. The only volumes that will not change are your losses to equipment, your boil off will be about the same as a single batch also.

Losses to trub and grain absorption will be related to the increase in grain bill.

If you are using a good program or spread sheet it will make the calculations for you.

 

[QldKev]

Hey anyone found a good BIAB mash volume for a 45-50L (in fermenter) batch, ie double batch? I have a 70L pot

I used to do a 50L (output) BIAB, but in a 82L keggle
I used
58L mash
6L sparge

QldKev

 

[technoicon]

i was thinking about 64l as well... last time i missed by heaps though.. but i calculated volume wrong

 

[stux]

I've just used an experimental biab calculator I'm working on to work to work out a few numbers for you

assuming 12L over 90min boiloff, and targetting 1.048

and End Of Boil Volume of 43L, which allows 3-5L of losses before you get less than the 38L into kegs you'd want

You'd want about 8.5KG of grain
62.5L of strike water which would give you 69.5L of mash. Grain displaces about 0.7L/KG

Start of Boil Volume at 100C would be about 56.5L at 1.038SG

Ending with your 43L target.

Your Into Boil (ie Mash Eff) efficiency would be about 80-82%

And you Into Fermenter (ie Batch) efficiency would be 70-74% if you ended up with 38-40L at 1.048.

 

[stux]

I've just used an experimental biab calculator I'm working on to work to work out a few numbers for you

assuming 12L over 90min boiloff, and targetting 1.048

and End Of Boil Volume of 43L, which allows 3-5L of losses before you get less than the 38L into kegs you'd want

You'd want about 8.5KG of grain
62.5L of strike water which would give you 69.5L of mash. Grain displaces about 0.7L/KG

Start of Boil Volume at 100C would be about 56.5L at 1.038SG

Ending with your 43L target.

Your Into Boil (ie Mash Eff) efficiency would be about 80-82%

And you Into Fermenter (ie Batch) efficiency would be 70-74% if you ended up with 38-40L at 1.048.

That's with no-sparge.

Any more grain, and you'd want to do a bit of a sparge or kettle topup, but you very quickly lose efficiency if you skip the sparge when you need a kettle topup.

When you're pushing your mash volumes, best to put your strike water in, heat it up to strike, pull it out 3L or so in a jug, add your grain, then top it back up with your reserved water right to the brim

 

[stux]

I've just used an experimental biab calculator I'm working on to work to work out a few numbers for you

assuming 12L over 90min boiloff, and targetting 1.048

and End Of Boil Volume of 43L, which allows 3-5L of losses before you get less than the 38L into kegs you'd want

You'd want about 8.5KG of grain
62.5L of strike water which would give you 69.5L of mash. Grain displaces about 0.7L/KG

Start of Boil Volume at 100C would be about 56.5L at 1.038SG

Ending with your 43L target.

Your Into Boil (ie Mash Eff) efficiency would be about 80-82%

And you Into Fermenter (ie Batch) efficiency would be 70% if you ended up with 38L at 1.048.

That's with no-sparge.

Any more grain, and you'd want to do a bit of a sparge or kettle topup, but you very quickly lose efficiency if you skip the sparge when you need a kettle topup.

When you're pushing your mash volumes, best to put your strike water in, heat it up to strike, pull it out 3L or so in a jug, add your grain, then top it back up with your reserved water right to the brim

 

[BeauVinnie]

That's with no-sparge.

Any more grain, and you'd want to do a bit of a sparge or kettle topup, but you very quickly lose efficiency if you skip the sparge when you need a kettle topup.

When you're pushing your mash volumes, best to put your strike water in, heat it up to strike, pull it out 3L or so in a jug, add your grain, then top it back up with your reserved water right to the brim

So the aim is to get as big a mash vol as possible without spilling over? By taking out the 3L-ish you allow the grain to displace the water without spilling over then topping up to the brim ya?

 

[RdeVjun]

So the aim is to get as big a mash vol as possible without spilling over? By taking out the 3L-ish you allow the grain to displace the water without spilling over then topping up to the brim ya?

I can't speak for Stux, but yeah that's pretty much it IMO. You can also use either the reserved water or some cold or hot to fine tune the mash temperature at that point.