Thinking of going down the BIAB route

[chuffer]

I have a home-made cooler mashtun and a 33L SS stock pot. Rather than using the mashtun and the makeshift sparging thing I do, I've been tempted to maybe look at BIAB. Now I'm kegging I don't need to do a full size 23L batch, 18.5-19L will prob suffice. On that basis, I'm concerned my 33L stock pot won't be big enough. Should it be twice the size of your batch (i.e. 37-38L if I'm doing 18.5 - 19L)? I guess I could prob do a smaller batch 17.5L and then top up with water / DME?

 

[samale]

I have 30 litre burco boiler I use biab. I normally get between 20-23 litres in the fermentor depending on gravity.

 

[MyQul]

Just make a concentrated wort and dilute in the FV. I used to make 23L batches using an 19L pot

 

[chuffer]

I have 30 litre burco boiler I use biab. I normally get between 20-23 litres in the fermentor depending on gravity.

How much water do you put in the boiler first though? I'm worried that, when I add the bag, the pot will overflow

 

[samale]

How much water do you put in the boiler first though? I'm worried that, when I add the bag, the pot will overflow

Trial and error. Again it's down to the amount of grain your using. I normally go 26 litres then a small sparge before the boil

 

[chuffer]

Trial and error. Again it's down to the amount of grain your using. I normally go 26 litres then a small sparge before the boil

I tend to go for 5 - 6% ish brews so grain bill is usually 5 - 5.5kg ish. Would you tend to do similar or lighter brews?

 

[samale]

That's my normal ball park as well. 5 -6 kg giving a 5%-6% beer.

 

[samale]

If I want stronger I up the grain bill and end up with slightly less in the fermentor. I don't use recipe calculators just go of experience of my system

 

[chuffer]

That's my normal ball park as well. 5 -6 kg giving a 5%-6% beer.

Cool, so the addition of 5-6kg of grain to your 20-23L of water, still means you don't manage to make the 30L burco overflow? If I'm readin that correctly then that's pretty reassuring

 

[PhilBrew]

Hi Chuffer

How much water do you put in the boiler first though?

... as a rule of thumb, dry grain displaces around 0.75 lts/kg ... just make sure you leave yourself enough headroom

Then to work the rest out ...

• to get 18.5-19 lts into a corny, you'll want 19.5 lts into your FV (to allow for 0.75 lts lost to yeast cake)
• to get 19.5 lts into your FV you'll need 22 lts in your boiler at end of boil (2.5 lts lost to trub and deadspace)
• to end up with 22 lts at end of boil, you'll need to start boiling 26 lts (4 lts evaporated off)
• to have 26 lts at start of boil, you'll need 31 lts in the mash (5kg grainbill, grain will soak up 1 lts/kg)
• and to start off with 31 lts of water you'll need a pot that'll take 34.75 lts (5kg grainbill, grain will displace 0.75 lts/kg)

... all the numbers in red are those that you have to estimate/caclulate/measure, for your system ... if you can't fit it all in at the start, leave a few lts out and add that to a separate vessel and incorporate a dunk sparge step after pulling your bag but before starting the boil.

Cheers, PhilB

 

[samale]

Just be cautious the first time. Go 25 litres to 5kg of grain. If you have space up the water the next brew.

 

[chuffer]

very useful folks, thanks very much....sounds like I shouldn't be too far off and saves me shelling out unnecessarily ££ for a 50L pot as I suspected I might have to