First BIAB, not sure what to do?

[Evil Phil]

So I bought an Exceedlingly Good IPA grain kit from HBC, and I've also bought one of these :



Which is basically a posh BIAB boiler with a re-circulation pump. The instructions from HBC don't include BIAB instructions, they just say follow that methodology. It comes with 4.5kg of grain, and the hops etc.

I don't know how much water should I use? I've read that for BIAB you should allow 6l of water per kg of grain to account for the mash and evaporation.

My thinking based on this research is the following.

6 x 4.5 = 27l of water.
Use 25l of water for 1 hour mashing at 67C
15 minutes mash out at 80C
Use remaining 2l for sparging after mash out
Then boil for the hour required, adding hops as appropriate.

Is this in the ball park? Here's the instructions I received if they help

Original Gravity 1.045 Alcohol 4.6%
Based on a 72% efficiency.

Wort volume for boil =281t
Mash vol 1 = 121t
top up with 8lt
batch#2 vol. =131t

So 121t for mash Then
21lt for sparging

Batch sparge method:
Mash all pre-crushed grain at 67 degree C for I hour in 121t of water. Top up after 1 hour with 81t of water at 80 degree C. Mix well and leave settle for 15 minutes. Drain and recirculate until runnings are clear. Drain the first batch to your boiler. Add the second batch of water, 131t at 80 degree C. Mix well and leave settle for 15 minutes. Drain and recirculate until running's are clear. Drain the second batch to your boiler.

Boil the wort for 1 hour adding the hops as labelled at the appropriate times (EG 60 minute hop goes in with 60 minutes to go, start of hod). Add the whirifloc tablet with 10 minutes to go in the boil. Once boil is complete, cool to 20 degree C and drain to the fermenter. Add your yeast.

[BrewDorg]

Have the same system so hopefully can help

Your figures seem ok, but the 6L/kg isn't very useful tbh. For example, if you have a 6kg grain bill then that formula says to use 36L of water. The best formula to use is similar to the grainfather formula - 2.7L/kg + 6.5L. The 6.5L is to account for the space beneath your grain basket. If you'd like to sparge less, the 2.7L figure can be pushed out. I often go to 3L or 3.5L depending on grain bill and it works fine. In your brew, you could use for example 4.5kg x 3L + 6.5L = 20L for your mash which will leave around a 10-12L sparge. Or you could use 4.5kg x 3.5L + 6.5L = 22.5L for your mash which will leave around 8-10L sparge and so on and so on

You can't really batch sparge with it either. After mashing and recirculating for an hour, your grain bed will be set, so you don't really want to mix it all up. Aside from that, the perforated bottom will just drain all your sparge water into the kettle below when you try to do a batch sparge. The best thing to do is pull the basket up, let it drain as much as possible, then fly sparge over the grain bed until you are at your desired pre-boil volume. If you really want to do a batch sparge, you need to be sure the total volume you're dumping in is correct ie. it will bring you to your correct pre-boil. Dump the water all in and mix it around, but just be warned that it will begin to drain straight away and it will be cloudy.

I don't really understand what is meant by any of this:

Wort volume for boil =281t
Mash vol 1 = 121t
top up with 8lt
batch#2 vol. =131t

So 121t for mash Then
21lt for sparging

[Evil Phil]

Thanks BrewDorg, I'll go ahead with a 22.5l mash and sparge to 28l and boil.

Think I need to look into a BIAB recipe book