BIAB Brewing (with pics)

[Domes]

I'll ask this here, since it seems to be the local repository of BIAB knowledge, and I haven't been able to find anything. I'm getting ready to do my first BIAB batch soon and was wondering, what ratio of water to grain do most people use for BIAB? 1.0-2.0 qt / lb is of course the recommended range for AG brewing, but it sounds like most people who aren't sparging are using a much thinner mash than this?

I ask because I would think (just from Michaelis–Menten kinetics) that efficiency would be reduced at extreme thinness (unless mashing for much longer), since the substrate concentration is reduced (and so the rate of conversion is reduced).

Use as much water as you can so that you end up with about 5.5 gallon when you're finished boiling. I use about 2.6 quarts/pound of grain. But every system is different. I crush my grains twice, mash for 90 minutes, stir and reheat half way through, mash out at 170 deg, and drain for about a half hour and consistently get 72% efficiency.

 

[FlyDoctor]

SiriusStarr gets an award for coolness - Michaelis-Menten Kinetics and beer...love it.

BUT - as someone who may know about biological reactions, you probably know that a 2 fold reduction in substrate concentration (the relative thinness compared with standard) is really nothing in biological terms - especially when one considers that amazing speed most enzymatic reactions run at. I would bet you would start to make a difference with a 10-fold reduction in substrates, but would be surprised if 2-3 fold would make much of a difference.

My data-free ideas...

 

[robcj]

Notes:
So, it's only one set of data but it looks like the squeeze is a total waste of time other than getting my pre-boil volume where it needs to be (I only picked up .0004 gravity points). I think I'll just add a tiny bit more starting water and stop wasting my time squeezing!

This very closely mirrors the results my friend and I have been seeing since we moved to a full volume BIAB process. We have found that the mashout has a positive effect of adding on average 4 gravity points but that squeezing was a waste of time. So we've stopped squeezing the bag at all.

We simply pull the bag, let it hang over the beam in the garage and drip down into the kettle as we bring it up to a boil. We're consistently achieving efficiencies of 80% and higher.

Squeezing the bag seems to be a given in most of the BIAB processes written up online so I'd be interested in hearing from other people who don't do it.

 

[Mysticmead]

squeezing works for some.. others get the same efficiency without squeezing. it all works and the best thing about brewing is you can find what works best for you.

 

[SiriusStarr]

SiriusStarr gets an award for coolness - Michaelis-Menten Kinetics and beer...love it.

BUT - as someone who may know about biological reactions, you probably know that a 2 fold reduction in substrate concentration (the relative thinness compared with standard) is really nothing in biological terms - especially when one considers that amazing speed most enzymatic reactions run at. I would bet you would start to make a difference with a 10-fold reduction in substrates, but would be surprised if 2-3 fold would make much of a difference.

My data-free ideas...

Haha, sorry, I'm a biologist, so this is how I perceive the world. XD

Well, it's all a matter of what the substrate concentration is. If the active sites are essentially saturated, then of course the process is rate-limited by the kcat of the enzyme and the enzyme concentration, and a two-fold reduction in substrate isn't going to appreciably change the rate. If the rate-limiting step is formation of the enzyme-substrate complex, then a two-fold reduction is substrate can result in a significant reduction in rate.

That being said, my guess is that alpha-/beta-amylase have pretty small Km's and we have a ridiculously high starch concentration while mashing, so it shouldn't (and it apparently doesn't, since BIAB wokrs) matter.

 

[WileECoyote]

This very closely mirrors the results my friend and I have been seeing since we moved to a full volume BIAB process. We have found that the mashout has a positive effect of adding on average 4 gravity points but that squeezing was a waste of time. So we've stopped squeezing the bag at all.

We simply pull the bag, let it hang over the beam in the garage and drip down into the kettle as we bring it up to a boil. We're consistently achieving efficiencies of 80% and higher.

Squeezing the bag seems to be a given in most of the BIAB processes written up online so I'd be interested in hearing from other people who don't do it.

Hello, (Me Not knowing any better) I wonder if squeezing the bag makes any difference if you only did a 60 min mash instead of 90?, and or doing a partial boil? as I can only pull off a 4 gal boil at the moment.
(I need a bigger pot lol)

Thanks and Cheers

 

[WileECoyote]

SiriusStarr gets an award for coolness - Michaelis-Menten Kinetics and beer...love it.

BUT - as someone who may know about biological reactions, you probably know that a 2 fold reduction in substrate concentration (the relative thinness compared with standard) is really nothing in biological terms - especially when one considers that amazing speed most enzymatic reactions run at. I would bet you would start to make a difference with a 10-fold reduction in substrates, but would be surprised if 2-3 fold would make much of a difference.

My data-free ideas...

Was that in english ?, LOL just kidding.

Cheers

 

[Mysticmead]

Hello, (Me Not knowing any better) I wonder if squeezing the bag makes any difference if you only did a 60 min mash instead of 90?, and or doing a partial boil? as I can only pull off a 4 gal boil at the moment.
(I need a bigger pot lol)

Thanks and Cheers

yes a partial boil makes a difference. if you can only do a 4 gal boil, make a smaller batch

 

[Fordzilla]

Sorry if this was already discussed. Whats the advantage of a 90 minute mash? I'm still new to BIAab but I seem to do OK with 60 minutes. Has anyone done any experiments with 60 vs 90 and compared efficiency?

 

[thughes]

Sorry if this was already discussed. Whats the advantage of a 90 minute mash? I'm still new to BIAab but I seem to do OK with 60 minutes. Has anyone done any experiments with 60 vs 90 and compared efficiency?

We are experimenting with this at another BIAB website.

Here are results of my last two brews:

brew#1
15 minutes: 7.4 brix/1.0282 (mash temp 154F)
30 minutes: 7.8 brix/1.0298 (mash temp 154F)
45 minutes: 8.6 brix/1.0329 (mash temp 154F)
60 minutes: 10.0 brix/1.0384 (mash temp 152F)
75 minutes: 10.5 brix/1.0404 (mash temp 150F)
I then ramped temp up to mashout (168F) over 15 minutes:
90 minutes: 11.2 brix/1.0432 (mash temp 168F)
I let it sit at mashout temp for 15 minutes:
105 minutes: 11.4 brix/1.0440 (mash temp 167F)
Pull bag and squeeze:
pre-boil: 11.5 brix/1.0444 (mash temp N/A)

brew#2
60 minutes: 7.4 brix/1.0282 (mash temp 154F)
end of 90 minute mash: 7.8 brix/1.0298 (mash temp 154F)
end of 10 minute mashout (168F): 9.0 brix/1.0345
pre-boil (after pulling and squeezing bag): 9.2 brix/1.0353

*(brix converted to sg using Sean Terrill's calculator)


Granted this is a very limited data set but it appears that:

A) the extra 30 minutes in the mash does indeed result in more extraction/higher gravity

B) squeezing the crap out of the bag may not be worth the extra .0005 gravity point!

 

[FlyDoctor]

We are experimenting with this at another BIAB website.

Here are results of my last two brews:

brew#1
15 minutes: 7.4 brix/1.0282 (mash temp 154F)
30 minutes: 7.8 brix/1.0298 (mash temp 154F)
45 minutes: 8.6 brix/1.0329 (mash temp 154F)
60 minutes: 10.0 brix/1.0384 (mash temp 152F)
75 minutes: 10.5 brix/1.0404 (mash temp 150F)
I then ramped temp up to mashout (168F) over 15 minutes:
90 minutes: 11.2 brix/1.0432 (mash temp 168F)
I let it sit at mashout temp for 15 minutes:
105 minutes: 11.4 brix/1.0440 (mash temp 167F)
Pull bag and squeeze:
pre-boil: 11.5 brix/1.0444 (mash temp N/A)

brew#2
60 minutes: 7.4 brix/1.0282 (mash temp 154F)
end of 90 minute mash: 7.8 brix/1.0298 (mash temp 154F)
end of 10 minute mashout (168F): 9.0 brix/1.0345
pre-boil (after pulling and squeezing bag): 9.2 brix/1.0353

*(brix converted to sg using Sean Terrill's calculator)


Granted this is a very limited data set but it appears that:

A) the extra 30 minutes in the mash does indeed result in more extraction/higher gravity

B) squeezing the crap out of the bag may not be worth the extra .0005 gravity point!

Nice work!

I'll add the extra grain to avoid the 30 extra minutes...but thats me. For me, the method is about simplicity in process, so a bit of extra grain to get the desired results on my system is worth it.

 

[thughes]

Thanks. This is exactly why I disregard all the "common knowledge" that is repeated as gospel and actually experiment to determine real world results for myself (on my system, with my processes, etc).

 

[thughes]

You'll also note that it appears the mashout gives me about .005 additional points.

 

[Mysticmead]

We are experimenting with this at another BIAB website.



A) the extra 30 minutes in the mash does indeed result in more extraction/higher gravity

B) squeezing the crap out of the bag may not be worth the extra .0005 gravity point!

nice data. next brew could you check and see how it compares when you either add extra water up front to compensate for not squeezing or adding top up water. To me that would be a little more diluted than if you squeeze the bag to get the pre-boil volume. Of course that's just MY preferred method and nothing is written in stone here

 

[MDHarris]

I'd like to know how much wort we are actually talking about in this "to squeeze or not to squeeze" question. Have you ever squeezed in a container separate from your boil pot and taken volume and gravity measurements? I haven't but am interested to know if we are talking about a pint, mabey 1.5 pints of 1.04 wort, or more like 2-3 quarts? If the case is 1-1.5 pints, would you continue squeezing or sacrifice the pint of wort for the saved time? I'd love to know the amount of grain used, the volume of squeezed wort and the gravity readings y'all come up with. I think this will help us put numbers with the question of weather to squeeze or not to squeeze...mabey

 

[Mysticmead]

I can squeeze 3-4 quarts...

 

[C-Rider]

I do small batches. Grain weight rarely over 5 lbs. So when I squeeze well really I PRESS using to coffee cups w/bag in a collendar I get a lot of liquid. Will have to take some measurements later this week when I brew.

 

[thughes]

I'd like to know how much wort we are actually talking about in this "to squeeze or not to squeeze" question. Have you ever squeezed in a container separate from your boil pot and taken volume and gravity measurements? I haven't but am interested to know if we are talking about a pint, mabey 1.5 pints of 1.04 wort, or more like 2-3 quarts? If the case is 1-1.5 pints, would you continue squeezing or sacrifice the pint of wort for the saved time? I'd love to know the amount of grain used, the volume of squeezed wort and the gravity readings y'all come up with. I think this will help us put numbers with the question of weather to squeeze or not to squeeze...mabey

With a standard 5 gallon brew (12+ lbs grain & 8+ gallons of water), I hang the bag over the pot and squeeze to reclaim .75-1 gallon of wort. We're not talking trivial amounts, that's why I prefer to squeeze rather than use a bit of extra grain and/or top up with plain water (and throw away all that good wort!).

 

[Antler]

My first AG brew I didn't add more grains, and I didn't do any sort of sparge(never do), I mashed for about 70 minutes then a 15 minute mashout. Did not squeeze the bag, just let drip into the kettle as it came up to boil and I got 78% efficiency!

 

[WileECoyote]

yes a partial boil makes a difference. if you can only do a 4 gal boil, make a smaller batch

Sorry, I didn't word that part of my question properly, what I meant to ask was, dose squeezing the bag makes any difference if you only do a partial boil, say 4 gal?

Your answer also brings another question to mind, if I were to BIAB a 5 gal recipe and mash it in 4 gal of water, can't I just top off to 5 gal in the fermenting bucket, with the same or close to the same gravity readings as mashing in 5 gal?

Or if its not the same, maybe adding some extra grain to compensate so I can top off?

Cheers

 

[WileECoyote]

With a standard 5 gallon brew (12+ lbs grain & 8+ gallons of water), I hang the bag over the pot and squeeze to reclaim .75-1 gallon of wort. We're not talking trivial amounts, that's why I prefer to squeeze rather than use a bit of extra grain and/or top up with plain water (and throw away all that good wort!).

WOW, 1 gal out of 8gal, thats a lot of wort, It sounds to me like the extraction doesn't change by squeezing the bag, but the volume of wort is what would affect the brew.

Cheers

 

[Mysticmead]

Sorry, I didn't word that part of my question properly, what I meant to ask was, dose squeezing the bag makes any difference if you only do a partial boil, say 4 gal?

Your answer also brings another question to mind, if I were to BIAB a 5 gal recipe and mash it in 4 gal of water, can't I just top off to 5 gal in the fermenting bucket, with the same or close to the same gravity readings as mashing in 5 gal?

Or if its not the same, maybe adding some extra grain to compensate so I can top off?

Cheers

to me yes squeezing makes a difference. but only in the volume of wort collected. On a typical grain bill I recover almost 1 gallon of wort by squeezing.

can you increase the grain bill or mash for 4 gallons using a 5 gallon recipe, sure ya can. but the added sugars could impact hops utilization. however, it shouldnt be much different than doing an extract beer.

 

[WileECoyote]

to me yes squeezing makes a difference. but only in the volume of wort collected. On a typical grain bill I recover almost 1 gallon of wort by squeezing.

can you increase the grain bill or mash for 4 gallons using a 5 gallon recipe, sure ya can. but the added sugars could impact hops utilization. however, it shouldnt be much different than doing an extract beer.

Thanks, I saw where you stated about squeezing 1gal extra wort out, that has to make a big difference in a 5 gal batch of beer, Im not exactly sure what percentage different that is, but off the top of my head (with out a calculator) somewhere around 12+ percent difference, depending on pre-boil volume.

Cheers

 

[MMJfan]

I have a BIAB question. I'm interested in doing an Oberon clone recipe using BIAB. The recipe I'm interested in uses decoction. My question is, has anyone done BIAB with a decoction mash? Or is it not worth the effort with BIAB?

 

[Mysticmead]

I have a BIAB question. I'm interested in doing an Oberon clone recipe using BIAB. The recipe I'm interested in uses decoction. My question is, has anyone done BIAB with a decoction mash? Or is it not worth the effort with BIAB?

yep... have done a decoction mash and if the clone calls for it do it.. I was very happy with the decoction I did on a hefe. I will be doing a decoction again in a month or 2 when I brew a nice malty german style lager (after I heal from my wrist surgery).

 

[Brewitt]

I have done a decoction on a Golden Strong Ale. Worked great. Not sure if it contributed anything in the end but the brew was good and the process was easy.

 

[marshallwms]

WOW, 1 gal out of 8gal, thats a lot of wort, It sounds to me like the extraction doesn't change by squeezing the bag, but the volume of wort is what would affect the brew.

Cheers

While squeezing, or letting the bag drip into the kettle while raising the wort to boil, doesn't seem to add a lot to the SG of the wort, obviously if you recapture 1 gallon of wort to a 7 gallon boil, taking it up to 8 gallons, you are adding about 14% more sugars to the total amount which will show up when the target post-boil volume is attained. (Sorry for the long sentence.) That is, if you boil down 7 gallons of 1.040 wort to 5 gallons, you end up with a lower SG than if you boil down 8 gallons of 1.040 wort to 5 gallons. So to me, squeezing or just letting it drip makes sense. And letting it drip while going from mashout temps to the boil doesn't take any work if you can suspend the bag somehow with a pulley or colander, etc.

 

[Brewitt]

+1 to marshallwms. I recover at least a half a gallon of wort from squeezing the grain my typical 5 gallon BIAB.

 

[JimTheHick]

+1 to marshallwms. I recover at least a half a gallon of wort from squeezing the grain my typical 5 gallon BIAB.

+2 it's all about the extra volume.

It's not that there is some secret 1.090 wort caged up on the grain bag!

 

[sidbedi]

Greetings! This thread inspired me to start tinkering with BIAB all grain about six months ago, thank you Seven. It is a great technique, a real revolution. In my constant quest to simplify and optimize I came up with a way to brew ten gallon batches very easily using a BIAB system with no extra equipment. I have made a video about it here if anybody is interested:

https://www.homebrewtalk.com/f36/sids-one-vessel-all-grain-brewing-system-360364/

The gist of it is to use multiple bags when you do a BIAB in a tall vessel to do 10+ gallon batches. I can do two ten gallon batches at the same time solo using this technique!

Enjoy!
Sid Bedi