Brief run down of BIAB

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keat64

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I've not considered Brew in a Bag, but would like to give it a go.
How does this compare to using a mash tun.

I assume, I drop my bag of malt in to my boiler, allow it to mash, lift it out and boil whats left ?
If thats's the case how do you sparge.
 
if you want to do BIAB as it should be done according to the purists you do not sparge. However you can sparge and the usual way is to dunk the grain bag in a separate container with the sparge water in to rinse the grains or you can use a strainer over your boiler and put the grain bag in this and kettle sparge over the grains into your boiler. The usual strainer is one of those extendable ones which will be large enough for the bag and to go over the boiler I think you can get them from Ikea etc
 
You don't really need to sparge, unless your efficiency is suffering. If you do want to sparge, just do it in another pot and tip the wort into your boiler.

I've learned a bunch by watching the fast homebrew guy on youtube. Appreciate not everyone will like this style of video, but the basics are all covered in 5 minutes flat.

 
Absolutely. It's a bit silly and irreverent and I like that. Sometimes, we as homebrewers, we get too wrapped up in the chemistry and science, and I think that going back to basic principles and not worrying too much about the minutiae is thoroughly refreshing.
 
I've not considered Brew in a Bag, but would like to give it a go.
How does this compare to using a mash tun. …
I had a chat recently with the Beersmith "support crew" on their forum: Apparently the BIAB technique was developed by the Aussies (or as I pointed out, "rediscovered" 'cos 70/80s UK home-brewing used all sorts of like, but cruder, mashing ideas) and it was a "full-boil-mash" (or "full-volume-mash") technique, a true "one pot" brewing technique. The Beersmith program treats BIAB as a "full-boil-mash". But "full-boil-mash" (i.e. no sparge) requires the volume to do it in, hence imaginative ways of sparging began to evolve such as the "dunk sparge". (EDIT: "full-boil-mash" is an ugly, not very descriptive term, but is what Beersmith uses: Basically means when the grain bag/basket is drained and removed the liquid goes straight to boil - i.e. no sparging at all).

I've started using this imitation BIAB technique in some circumstances. Actually using a Grainfather to perform a "full-boil-mash" (the grain basket is just a rigid bag!). It's very quick! And no separate sparge water heater to organise. But the space in a Grainfather limit beers to about 23L at 5% ABV (I use the technique for brewing abstention day "beer" at 0.5% ABV, but have my eye on something stronger).
 
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I use the Klarstein (or rebranded Ace and others!) which has a metal 'colander' insert for want of a better word, that sits on inside the kettle for the mash, than lift it out and sit it on a metal ring (included with the kettle) and sparge through the colander with hot water, works for me
 
I use the Ace boiler for my mash water, then while it's mashing i refill the ACE for the sparge.
Then transfer the wort back to the boiler for boiling.

If BIAB doesn't sparge, then when i lift the bag of grains out, i'll only have half a brew to boil..
Is the BIAB mash performed at say a boiler full rather than 2.5l per kilo of grain.
2.5l per kilo would only give me a 12.5 litre boil volume.
 
I use the Ace boiler for my mash water, then while it's mashing i refill the ACE for the sparge.
Then transfer the wort back to the boiler for boiling.

If BIAB doesn't sparge, then when i lift the bag of grains out, i'll only have half a brew to boil..
Is the BIAB mash performed at say a boiler full rather than 2.5l per kilo of grain.
2.5l per kilo would only give me a 12.5 litre boil volume.
If you are doing BIAB you can forget the 2.5L/Kg water/grain ratio. The idea is you lift the grain bag out and the liquid left in the boiler is the amount you want to boil to end up with the batch size you want. If the full amount of water with grain doesn't fit in the boiler then you do a "dunk sparge" (or conventional sparge - but that can get messy dealing with a "bag") and/or top ups before and/or after the boil.

You can get really farty about calculating how much water you need at various points, but it's not really in the spirit of "BIAB". All the same, it's what I do with Beersmith calculating all the amounts, etc. and then translating it for the Grainfather which really wasn't designed for "no sparge" and "full volume mashes". But I like getting "farty", and there really isn't a need to.
 
Full BIAB you typically use one vessel and that vessel will need to be usually around double the volume you want in your FV
You're probably right. But I'm planning to get a 22L "full BIAB" batch out of a 30L boiler (re-jigged Grainfather). But, I've no done it yet!
 
I don't feel that there is much point in going to all the trouble of a brew day to make only a 15l brew.
I'd want to squeeze as much in to the 30l Ace as physically possible.
I usually aim for a 23-25l boil if I can.
I may even hold some extra wort back for a late top up.

5 kg of grain would probably utilise a 15l fluid space.
If I had to perform a dunk sparge, i'd need another method of boiling the dunk sparge water, as my boiler would now be half full of wort.

I can see that BIAB has advantages in the respect that it may save an hour, and less faffing about transferring from one vessel to another, but if this is at the cost of a smaller brew, then maybe i'll stick to what I know.
 
Two beers I'm planning (21.6L batches - what will fit in my Corny kegs) are just short of 5% ABV. But that will be too much for my 30L Grainfather, so I'll probably hold back 4-5L of water and just use that as boiler top up after the grain is removed.

But pushing the volume limits with the likes of a Grainfather will not be as "iffy" (potentially messy) as using a floppy BIAB bag. You'd probably need to start with something about 3.0-4.0% ABV (at 21-23L) to see how it works.
 
if you want to do BIAB as it should be done according to the purists you do not sparge. However you can sparge and the usual way is to dunk the grain bag in a separate container with the sparge water in to rinse the grains or you can use a strainer over your boiler and put the grain bag in this and kettle sparge over the grains into your boiler. The usual strainer is one of those extendable ones which will be large enough for the bag and to go over the boiler I think you can get them from Ikea etc
DOH!!! ..... I meant to do this when I brewed on Saturday and forgot
 
I don't feel that there is much point in going to all the trouble of a brew day to make only a 15l brew.
I'd want to squeeze as much in to the 30l Ace as physically possible.
I usually aim for a 23-25l boil if I can.
I may even hold some extra wort back for a late top up.

5 kg of grain would probably utilise a 15l fluid space.
If I had to perform a dunk sparge, i'd need another method of boiling the dunk sparge water, as my boiler would now be half full of wort.

I can see that BIAB has advantages in the respect that it may save an hour, and less faffing about transferring from one vessel to another, but if this is at the cost of a smaller brew, then maybe i'll stick to what I know.
Boil your sparge water first and set aside to come down to temp while you get on with your mash
 
5kg in about 27L water will require about 30L of space. With the bag removed (it will retain about 4L liquid) the level will drop to about 23L which boiled for an hour will result in about 18.75L which'll cool to about 18L (calculated with Beersmith). No sparge. Perhaps a bit short, but could be topped up by 5-6L before boiling to get a 23L batch out. Pushing the boundaries, but feasible.
 
I'll have to have a play next time.
Maybe a kettle or two of water over the removed bag might give me the extra top up.
Call it 'half a sparge.'
 
You're probably right. But I'm planning to get a 22L "full BIAB" batch out of a 30L boiler (re-jigged Grainfather). But, I've no done it yet!
I use a 50l pot.

A full biab water for a 23l is around 32liters of water. Add the grain and I am up to about 35 - 40l total.

Not sure how you'd do that with s 30l pot unless your going to top up
 
… Not sure how you'd do that with s 30l pot unless your going to top up
Read on, and I explain that (#14). As for topping up, see #17. But I'm not the only one writing half-cock posts: You don't give any idea how much grain you add to make an extra 3-8L of volume. A lot I feel 'cos I expect 5Kg to add only 3L of volume (when mixed).
 
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