More NEWB questions: Differences between BIAB and AGB?

What really is the difference between BIAB and AGB? Or rather, correct me if I am wrong with my assessment of the two:

BIAB: Use a single large kettle with a bag in which you create a mash with grains or mash with partial grains/partial malt extract. Go through the "mash" process...then use the bag to remove the spent grains leaving the wort behind. Boil, then ferment, then bottle.

AGB: Use one kettle/cooler for mash. Empty some of the extract out and pour over mash to use the grain bed to clear the extract. Once clear, tap off into a 2nd kettle for boiling.
Boil, then ferment, then bottle.

Am I missing something here? If I am not, then please explain why someone would go through the extra work and the need to purchasing a 2nd kettle/cooler for use as a mash tun?

I appreciate the education.

Tradition.

I like using a mash tun, it keeps the temps constant no turning heat on and off to maintain mash temps.

Both are a method of all grain brewing.

BIAB typically uses 1 vessle and a bag, all the grain is mashed in that pot and then the bag is removed typically with no sparge, drained and you continue on with the boil.

Traditional AG is using 3 vessles, HLT,MT (mash tun) and a BK (boil kettle). the hot water is heated in the HLT then put into the mash tun for a set amount of time to mash, then is sparged with more hot water to further rinse more sugars out and that goes into a BK where you continue with the normal boil.

that is the short of it, you can read for hours on this subject.

Youve got the basics of it down. BIAB is a form of AG that uses a single vessel. For me, I like the relative simplicity and ease of BIAB but I can understand how some people may prefer the more traditional multi vessel approach and a mash tun likely gives greater temperature control as well as more sparging options.

The trade off is efficiency. With BIAB you often need to add a little bit of extra grain, especially if you are doing BIAB with no sparge, as it seems most people do who BIAB. I did BIAB before I drilled some holes into my mash tun to convert it into a proper one. When I did though, I usually sparged by dunking the grains into another pot. With BIAB no sparge, my efficiency was around 65% +/- 5 or so. BIAB with a psuedo-sparge bumped it up to 68-72%. Now with regular AG, my efficiency is right at 77-78% every time. I think that sparging gives you some consistency, since you are approaching that limit of possible sugars extracted. Keep in mind that the big jump in efficiency had a lot to do with volume control and improving my process. When I did BIAB I pretty much just eyeballed sparge volumes and such (but always mashed in the traditional water to grist ratio).

BIAB is just a subset of all grain brewing (if you don't use extract). The main difference is the method of lautering. BIAB just uses a mesh filter, and traditional AGB uses the grain bed as a filter, allowing you to vorlauf and to get a clearer wort.

For me personally, I only do BIAB if I want to do a test batch around 2 1/2 gallons. After the rest period, I then lift the bag up, put it in a colander over the pot, and let it drain for a few minutes. I then pour some sparge water over it to rinse it, and then I let the drain for a few more minutes. After that, I put the colandar over another pot and start heating up the wort. Before the wort boils I put the bag in another pot, and then dump that wort from the 2nd pot into the main pot and the go as normal.

If I'm doing 5 - 6 gallon batch, then I always do a mash tun and batch sparge.

dbsmith said:

The trade off is efficiency. With BIAB you often need to add a little bit of extra grain, especially if you are doing BIAB with no sparge, as it seems most people do who BIAB.

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I get 75-78% with BIAB with no sparge and don't bother to even squeeze the bag until it's bone dry so this isn't true if you do a finer crush

JeepDiver said:

I get 75-78% with BIAB with no sparge and don't bother to even squeeze the bag until it's bone dry so this isn't true if you do a finer crush

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True, crush matters a ton. I only crush my grain once through the LHBS mill.

With a traditional 2 or 3-vessel system, you can make larger batches than with an equivalently-sized single vessel BIAB just due to the volume of the grain taking up otherwise available space in your kettle.

And for very high OG batches, I think that having an extra vessel will net you better effiiciencies, regardless of how BIAB performs for smaller gravities, because you have more options for second and third runnings such as performing a partigyle, etc.

Weight- if you have 24 lb. of dry grain, and put that in a bag, it can't be safely lifted out.

For smaller batches, it's about efficiency.

Cyclman said:

Weight- if you have 24 lb. of dry grain, and put that in a bag, it can't be safely lifted out.

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Sure it can. Why do you think it cannot?

For smaller batches, it's about efficiency.

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No, it's not. Already been discussed.

Cyclman said:

Weight- if you have 24 lb. of dry grain, and put that in a bag, it can't be safely lifted out.

For smaller batches, it's about efficiency.

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my rig has a metal basket that the sack goes into. it could easily support 50 lbs if it needed to. a simple overhead pulley is a highly effective force multiplier.

BIAB looks like an interesting thing, and I am convinced it would work... but for me... it seemed like a simpler, cleaner, easier process to make a MLT in a cooler (which I already Had), and keep my 8-Gallon kettle.

There is NOTHING to be afraid of with either method. I think You just need to look at where you're at with equipment now, and see what the shortest path is to AG and do that.

My setup is sort of a hybrid system. I have a cooler for a mash tun, but use a bag instead of a false bottom. I squeeze the bag for full extraction and get ~85% efficiency.

I prefer mini-BIAB at the moment in a 5 gallon pot, and as mentioned, I get anywhere from 65%-75% efficiency depending on crush size and length of the mash. Typically, I do 153f for 70 minutes always using 2 row as a base malt. I plan on upgrading my brewing space to a 10 gallon pot by the end of the year after I get my garage cleaned out a little bit and as previously mentioned, a pulley system for suspending the grains while they drain is going to be a necessity.

The only reason i'm even doing that, is my oldest Daughter can't stand the smell of hops and really need to move my brewing operation outdoors. Otherwise, i'd make everything stove top.

JeepDiver said:

I get 75-78% with BIAB with no sparge and don't bother to even squeeze the bag until it's bone dry so this isn't true if you do a finer crush

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Just a thought. Even though your efficiency is great and most people would be completely happy with it (including myself), it doesn't take away from what I said about still getting a higher efficiency with a sparge. You would still have even higher numbers if you sparged, all things being equal including crush. Finer crush is a compensation technique. Whether or not you actually want those higher numbers is another topic completely though.

dbsmith said:

Just a thought. Even though your efficiency is great and most people would be completely happy with it (including myself), it doesn't take away from what I said about still getting a higher efficiency with a sparge. You would still have even higher numbers if you sparged, all things being equal including crush. Finer crush is a compensation technique. Whether or not you actually want those higher numbers is another topic completely though.

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A finer crush isn't a compensation technique. It's actually a better way to get the most conversion, the more starch available for interaction with the enzymes the better. You just can't mash that fine with a normal sparge or you would get a stuck sparge

dbsmith said:

The trade off is efficiency. With BIAB you often need to add a little bit of extra grain, especially if you are doing BIAB with no sparge, as it seems most people do who BIAB. I did BIAB before I drilled some holes into my mash tun to convert it into a proper one. When I did though, I usually sparged by dunking the grains into another pot. With BIAB no sparge, my efficiency was around 65% +/- 5 or so. BIAB with a psuedo-sparge bumped it up to 68-72%. Now with regular AG, my efficiency is right at 77-78% every time. I think that sparging gives you some consistency, since you are approaching that limit of possible sugars extracted. Keep in mind that the big jump in efficiency had a lot to do with volume control and improving my process. When I did BIAB I pretty much just eyeballed sparge volumes and such (but always mashed in the traditional water to grist ratio).


BIAB is just a subset of all grain brewing (if you don't use extract). The main difference is the method of lautering. BIAB just uses a mesh filter, and traditional AGB uses the grain bed as a filter, allowing you to vorlauf and to get a clearer wort.

Click to expand...

I do only BIAB and my efficiency is always in the high 70's Sometimes in the low 80's. No sparge but since I rarely use more than 6 lbs of grain I can get every last drop of liquid out of the grain. My bataches are just below 2 gallons each = 17 bottles.

dbsmith said:

True, crush matters a ton. I only crush my grain once through the LHBS mill.

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I also crush at the LHBS, but I run my thru twice.

JeepDiver said:

A finer crush isn't a compensation technique. It's actually a better way to get the most conversion, the more starch available for interaction with the enzymes the better. You just can't mash that fine with a normal sparge or you would get a stuck sparge

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True, but then you could add rice hulls, which would be another compensation technique. It doesn't matter what is called the compensation technique, it just depends on perspective. The most ideal crush would be for the endosperm to become flour and the husk to be minimally shredded. I don't think that conversion is the concern here. I'm talking about brewhouse efficiency. I'm still gonna say that no matter what you do with BIAB, if you don't rinse your grains you are going to have sugars all over the surface area of your grain that is not going to make it into the brew kettle. Is it enough to make a difference to you? Your call.

Captain Damage said:

... I squeeze the bag for full extraction and get ~85% efficiency.

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Yeah, same here. I'm not sure how BIAB got a bad rap for efficiency. If anything, it's the other way around due to the fact that you can practically turn your grain into flour and never have to worry about a stuck sparge. Anybody who's doing BIAB and not getting 80-85% efficiency, even with large OG brews is not doing it right. My default efficiency setting in Beersmith is 85% and I routinely hit my numbers. Even for large grain bills, I have never had less than 75%. The only thing I do differently when it comes to BIAB is that I do a 1-gallon sparge after I pull the bag. I pour a gallon of 170° water over the grains and let it drain into a bucket, then squeeze the bejesus out of the bag to get every last drop.

Correct me if I'm wrong, but my impression is that for the standard MLT setup, 70-75% seems to be the norm. I only assume this because most of the AG recipes posted on the forum have that as the expected efficiency. I pretty much always have to back off the grain bill on forum recipes so that I don't overshoot with my system.

As far as the OP's question: the difference is all in the process. The ingredients and end result are the same. Do whichever makes the most sense for you.

dbsmith said:

I'm talking about brewhouse efficiency. I'm still gonna say that no matter what you do with BIAB, if you don't rinse your grains you are going to have sugars all over the surface area of your grain that is not going to make it into the brew kettle. Is it enough to make a difference to you? Your call.

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A lot of us BIABers (yes yes I am one of them...) get pretty good efficiency. I actually do a two vessel system. Mash in one closed pot, insulated, sparge with the rest of the water needed for the boil at around 170. It's a dunk type sparge but it works pretty darn well.

Now I have very little equipment and rely a lot on being able to lift somewhat heavy things and hold a soaking grain bag over the pot, so if you can't do that or don't care for it, that would be another concern. I feel like if you're getting into pulleys and stuff like that why not just go with the traditional system? But that's just my opinion, to each their own.

lowtones84 said:

A lot of us BIABers (yes yes I am one of them...) get pretty good efficiency. I actually do a two vessel system. Mash in one closed pot, insulated, sparge with the rest of the water needed for the boil at around 170. It's a dunk type sparge but it works pretty darn well.

Now I have very little equipment and rely a lot on being able to lift somewhat heavy things and hold a soaking grain bag over the pot, so if you can't do that or don't care for it, that would be another concern. I feel like if you're getting into pulleys and stuff like that why not just go with the traditional system? But that's just my opinion, to each their own.

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Very true. When I used to BIAB I never thought about it, but then I broke my arm playing football, and things like this started showing up. I couldn't even bottle my own beers. Old people would be screwed trying to lift a heavy bag. If you already have a pulley, awesome, but yeah I would rather just go traditional rather than bother with all that.

I'm been thinking about switching from typical AG to BIAB due to lack of storage space. My wife and I just recently moved to a smaller house to be closer to family and are expecting our first child, so guess who's losing what little storage space he has. Anyway.....my question has to do with building a recipe. My understanding is BIAB is just like AG except your using one vessel. So the recipes should be the same except for the efficiency difference...right? I figure I need to do a few BIAB's with my current recipes to get an idea of what my efficiency will be and then just adjust accordingly. Thanks for the help!

Do a BIAB or two to see if you lose efficiency. I do a modified BIAB with a Sparge and get 80-85% efficiency. The sparge is a dunking in a plastic bucket with warm water so really not any more equipment and about 15 seconds to clean at the end of the day.