BIAB - A simple guide to formulating recipes.

[Eoin]

I hear a lot of people talking about biab calculators and the like, but to be honest I've never seen the need.

I have one simple tip.

Make up your recipe to a particular volume, say 55l and then work out the ingredients to get your gravity, as you would with a non-BIAB recipe.
Then mash etc and at the end, you either need to backliquor to get to where you wanted to be, or you boil for longer to reduce the amounts in your pot. It is helpful
if you have a sightglass or a method of knowing your volumes in your brewpot, I am lucky in that my 75l pot is also 75cm high so I can simply measure the height from the top of the wort to the rim of the pot and subtract.

This does take a few goes to get to know your system, but I know for example that in my 75l pot I start the mash with 65l strike water then put in my grainbill, I will be right to the top of the pot for the mash.
Once I pull the bag, I squeeze it to get all the goodness out, get the grist as dry as possible. Then start the boil.
At that point I am just trying to get to my volume, a longer boil won't make that much difference and if you use a hop sock you can remove your hops in line with the hop addition times so that your IBU values are correct.
I know that an hours boil will get me to about 55l leaving the pot. If I want a stronger beer then I can brew higher gravity and simply dilute to volume.

I realise some are allergic to the idea of dilution, but every large brewery does it.

Once you get to the final volume that was in the formulated recipe, if you've done everything else right then the numbers should match, remember you're not working out strike water and sparge water volumes here as with a trad setup.

That in a nutshell is how to brew a particular volume using BIAB.
No calculators...no bullshit.

[ColmR]

I agree. Once you've done a few BIABs, you get to know your system and don't need to worry about converters or whatever.

My approach is slightly different in that I've started treating my BIAB as a standard process. I basically take a standard recipe like something out of Brewing Classic Styles and do a mash as normal in the pot. Then I take out the bag and to get the volume up I do a batch sparge in a  bucket. I obviously need a second pot (HLT or whatever) but that's only really being used for sparge water so up to 10L or so. My efficiency and gravity numbers have spot on. My batch size is 20L or so.

[sub82]

Looks good!

For BIAB we always mash in less water to avoid diluting the enzymes too much and then make up to the preboil volume by sparging, so enzyme dilution mustn't be an issue then?

[Eoin]

Looks good!

For BIAB we always mash in less water to avoid diluting the enzymes too much and then make up to the preboil volume by sparging so enzyme dilution mustn't be an issue then?

I mash full volume and as originally specced BIAB is a full volume method, I have never had an issue with enzyme dilution, my recent Oud Bruin this weekend.
My target was 44L @ 18 Plato, I hit 42l @ 18 Plato, so I left it at that, decided it was so close as to forget the difference.

I never see any issue with enzyme dilution

[rAdve]

I also sparge so I can get to right boiling volume. Do you do mashout?

My stove top isn't powerful enough so I use heat stick to help it. I was wondering, should I sparge before mashout or what would be the right way to do it?

I also put my bag to colander in an other pot while I raise my main pot temperature to mashout temperature. Then I can insert bag again to main pot to do the mashout. On what step should I sparge to get full boiling volume?

[Eoin]

I also sparge so I can get to right boiling volume. Do you do mashout?

My stove top isn't powerful enough so I use heat stick to help it. I was wondering, should I sparge before mashout or what would be the right way to do it?

I also put my bag to colander in an other pot while I raise my main pot temperature to mashout temperature. Then I can insert bag again to main pot to do the mashout. On what step should I sparge to get full boiling volume?

I start at 65l and work backwards towards 55l, I have such a large pot and the wort moves so freely that I do not sparge at all. I can't help you on those questions unfortunately.

There are lots of BIAB derivatives and some of them use sparge steps, but this isn't "true" BIAB as it was originally specced as I said before. I've no issue with that but don't have experience of sparge steps.

Look up mini or maxi BIAB, as that is closer to what you are doing and it's well referenced around the web.

I also don't bother with mashout. I honestly think it is less relevant once I lift my bag, it's done.





Photos just so you can have an idea of the boiler I'm dealing with.