Planning my first BIAB

The Homebrew Forum

Help Support The Homebrew Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Portreath

Landlord.
Joined
May 9, 2018
Messages
591
Reaction score
186
Location
Cornwall
Hi

I’m now planning my first BIAB brew day. I’m going to start of with a Midland Mild recipe. The combined weight of the grans is approx. 3.4kg, and I’m aiming for a 19 litre brew. As this is a fairly low ABV brew (3.4%) I don’t want to end up watering it down too much. I’ve just bought a 25ltre Electrim mashing bin. I’ve filled the bin with 26 ltr of water and dropped the 3kg of grain in and submerged it to measure the displacement (grain was in a water proof bag):nod: and it looks fine, no overspill. Does 26ltr sound about right to end up with 19 ltrs of liquor in the end?
Thanks
 
Last edited by a moderator:
Do you mean 3.4kg of grain?

I think you'll be close to 18.5-19ltrs after your boil (assuming it's a 60m boil). But unless you transfer all of this to the fermenter, you'll lose some volume as trub. I usually leave about 2litres or so of trub in the boiler.

That is, however, a personal preference. Some people transfer all the wort, trub included, into the fermenter.
 
Opps, that should be 3kg of grain! I have taken the recipe from CAMRA'S brew your own British Ale, and the boil time is 90 mins, and the mash time is 90 mins also.
 
Last edited:
To calculate the volume of the mash once the crushed grain is doughed in, add 0.67 to the mash thickness (in litres per kg), then multiply that by the weight of the grain (in kg). In your case this gives you 28L. If you squeeze the bag (and I do) then the grain absorbion will be about 0.8 litres per kg of grain. So you will have about 23.5L after mashing. You will have to tailor the boil off and trub loss / dead space to your set up once you've done a brew, but 3L boil off and 1.5L loss is reasonable, leaving you with 19L into the fv. I'd recommend giving it a couple of good stirs during the mash to help with the efficiency. At the moment your recipe looks to be about 70% brewhouse efficiency, which is possible for a no-sparge full volume BIAB, but I suspect you will need to squeeze the bag to get there.

Best of luck with your first AG!
 
Thanks for the really useful advice and guidance. I do plan to try a short 1 ltr or so sparg, I just picked up a plastic garden riddle/sieve from home base, which with a little mod sit on top of the mash bin nicely. The recipe I has is based on Banks's Hanson's Mild (I sank a few of these as a youngster!!)
For the mash:
2630 grams Pale malt
295 grams Crystal malt
57 grams Black malt
And for the boil
Fuggle hops 17 grams
Golding hops 15 grams
 
Has the Electrim got a tap? If so fill with water just abouve the tap and drain until it stops, this gives you the dead space. close the tap and fill the bin up with careful measurements so you know exactly how much has gone in. I filled mine with 16litres (on top of the dead space water) and used a dowel wooden stick to mark this. Make the dowel just touch the top of the water line, and then mark on the dowel 16litres. I then filled with 1 litre each time and marked on the stick.

This lets you see how much water above dead space you have as that water won't go into your FV. I found this a really helpful way of working out boil off rates and a quick way of filling the correct water amounts.

In terms of BIAB, I fill with 20 litres (I have a 30l boiler) usually using about 4kg of grain, then as others have said drip the bag, squeeze the bag a bit, then pop bag in spare FV. use dowel to measure water level, then add top up sparge water to the FV and leave for 20 mins so I achieve a pre-boil volume of 25litres. Technically not 100% BIAB, but my efficiencies have only once been below 80% and very good.

You need to work out max boiling capacity you can get in the 25l bin, and then adjust from there. Hope this helps.
 
More good advice there. I'll add, if you are going to do a sparge, don't bother with only doing a litre. I also get >80% efficiencies doing BIAB, where I collect half the wort from the first runnings and the other half from the sparge, bag-squeezing after each. This means mashing with half the boil volume plus the dead space and grain absorption, and then sparging with half the boil volume.
 
The advice here is awesome, and I'm feverishly making notes getting ready for the brew day next week.
I'm not sure of the yeast yet, I was thinking maybe Danstar windor or Safale S04.

Yes, the mash tub has a tap, from the bottom of the tub to the tap inlet pipe (at the point where when level the water will stop flowing) is 3 cm
 
I'd wouldn't use wouldn't use Windsor for your first brew until you get the hang of things as it can finish high until you get used to how to use it; if you want a bomb proof yeast that suits this style really well, try Mangrove Jack liberty bell, which I can highly recommend in a dark Mild. Seems to suit the style really well.
 
Not come across that one yest, I have their cider yeast though. Just looked for a price and there are some sellers on Amazon that look to be over charging for this. Do you have a supplier you can recommend?
 
Awesome, I'm going to order a few and give it a go. Thanks for the tip. I was originally planning on using this (Mangrove Jack's Craft Series Yeast - UK Dark Ale M03) but it appear to be out of stock with all three supplier I use!!:?:
 
Don't let me put me off Windsor in the long term; lovely fruity yeast apparently, just perhaps not one to start off with.

Mangrove hacks M03 has now been replaced with their Empire Ale yeast - like Windsor it is reported to be lovely and fruity but can under attenuate. Again, perhaps one for later batches once you have your process down to a T and can start experimenting which yeast gives you the best results for each style?

I really like liberty bell for mild, however.
 
JJsh, always happy to take advice on board, and thanks for taking the time. I've ordered the yeast so hopefully brew day should be some point during next week. Apprehensive, but excited and eager to get stuck in.

So I've followed the advice and identified the dead space, and I've worked out the 19 ltr mark on the mash bin which is what I'm aiming for. Now I just need to factor in the loss from the grain bag absorption, and the boil off. I suppose I can only find out the latter through trial and error?
DSC_0039.jpg
 
trial and error is the key. I got really hung up on trying to perfect everything really early on. what you want is drinkable beer, but to enjoy it. Make sure you write everything down; how much you started with, how much at the end, how long it took, how long from mash to boil etc etc. - oh yeah make sure you can always see a clock!!!!!!!

I forgot to add that I also do the step Iain M speaks of when 'sparging' - open the tap into a spare FV and get a jug and scoop the runnings out and back over the grains (wear gloves as it's hot). It's interesting to see how the colour/clarity of the runnings chage as you do this but again this might be OTT for initial BIAB attempts.

As I mentioned before, it has to be as much about enjoyment as making good beer, otherwise whats the point? Have fun and keep us updated.
 
It was a few brews before I wrote a detailed, step by step plan of everything that needed to be done on brew day. I still use it as it means I'll never accidentally miss something out.

Probably the best advice I could give for a newbie - have a plan. And if things happen on brew day that you weren't expecting, or that you could do better, write it down and update your plan for your next brew.

Also, try and relax and enjoy it.
 
Thanks for the advice, I will be taking it all on board. Brew day is planned for Monday 11th June (day off work) and I plan to record the process, and post up a sup-date here soon after.

Cheers
 

Latest posts

Back
Top