BIAB Disadvantages to go with the Advantages thread.

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burtom

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Just looking for the other side of the coin. Are there any real disadvantages to BIAB?
 
Lifting heavy/hot bags or baskets sucks abit. 10gal batches are near impossible to lift alone...

That's only true if your situation won't allow you to set up an overhead lift. I can raise the bag for a 5gal batch with one hand with my two pulley rope hoist. The bottom pulley is ratcheting, so it safely holds the bag in place until it is released.
 
That's only true if your situation won't allow you to set up an overhead lift. I can raise the bag for a 5gal batch with one hand with my two pulley rope hoist. The bottom pulley is ratcheting, so it safely holds the bag in place until it is released.
I knew this was coming and left my comment the same... I meant alone without added help from anything or anyone. But yes like most problems there is a solution. =]
 
I haven't tried it yet, but from what I have read Step Mashing is a bit more complicated with BIAB. You don't want to apply direct heat to the grain bag and adding hot water could easily throw your numbers off. I'm pretty much going to avoid it unless it's absolutely necessary.
 
I haven't tried it yet, but from what I have read Step Mashing is a bit more complicated with BIAB. You don't want to apply direct heat to the grain bag and adding hot water could easily throw your numbers off. I'm pretty much going to avoid it unless it's absolutely necessary.

Mashing in a kettle is difficult too. Step mashing my hefeweizen was drove me to try BIAB. It was either do the math for multiple infusions or go BIAB and just raise the temp. What sucked was hand holding the bag off the bottom while I stirred the wort beneath. Pulleys only help if you have some place to hang them.

Really? Weird I just wrap the kettle with auto insulation and I maybe drop 2F threw out the hour. After the initial grain drop of course.

I've had the temp issues too. I wrapped my kettle in 3 moving blankets and it still loss 4F in 30 min.
 
To each his own but I cannot imagine how a 2-4f loss in 60 minutes means much at all considering that most of the conversion happens in the first 20 minutes or so. I don't wrap my kettle nor turn on the element to warm up the mash and I always hit my target gravity. It is really easy to get caught up in the minutia but that is the beauty of homebrewing, do or worry about what matters to you.
 
To each his own but I cannot imagine how a 2-4f loss in 60 minutes means much at all considering that most of the conversion happens in the first 20 minutes or so. I don't wrap my kettle nor turn on the element to warm up the mash and I always hit my target gravity. It is really easy to get caught up in the minutia but that is the beauty of homebrewing, do or worry about what matters to you.

I've had more of an issue with temp loss during step mashes. Otherwise I just use a 13gal cooler and full volume batch sparge. The coolers easier to clean out with a quick spray from the hose. I find I have to turn the bag inside-out a few times to get all the grain off of it.
 
Conversion is not a simple thing that is done once it's done. I think this is an oft-stated half-truth among homebrewers.

First of all, at lower mash temps where beta amylase is the primary worker, conversion takes much longer than with alpha amylase at higher temps. So it's not enough to state a fixed period of time like 20 minutes for how long conversion takes. It's entirely dependent on the temperature.

It is true that all starch may be converted to sugars after a given period of time. But enzymatic activity is still occurring in the wort. A mash that drops in temperature over an hour or more experiences further breakdown by beta amylase of the long chain dextrins created by alpha amylase. In this way, a mash that cools precipitously can produce a far more fermentable wort, and hence a higher ABV end product than desired.

Beta amylase does not denature like a light switch at higher mash temps. It is a gradual process. So as the temperature drops, any beta that hasn't denatured is continuing to work.

Now in the end, none of this really matters that much unless you are aiming for a particular result in the fermentability of the wort. Mashing is really quite forgiving in the end. But this is why some brewers obsess over temperature control, and others just relax and have a homebrew.
 
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Here's a disadvantage to BIAB that's easily overcome, but often isn't given how brewers typically practice brewing in a bag:

BIAB differs from traditional all-grain brewing in terms of what is removed after the mash: In traditional brewing, we remove the liquid wort from the grain. In BIAB, we remove the grain from the liquid wort.

In traditional brewing, before lautering to collect the wort, a step is first taken to settle the grain bed so that clear wort can be removed. This is called vorlauf.

In BIAB, typically the bag is just pulled out and drained, or optionally squeezed. There is no grain settling. Additional particulate matter always ends up in the boil, sometimes a lot.

While clear beer doesn't seem to be a particular problem with BIAB (despite early belief), some brewers dislike this additional particulate matter regardless. So that is a disadvantage to BIAB when performed in the standard way.

However, it's pretty easy to mitigate this with only minimal extra effort, although it's rarely discussed. You can recirculate during the mash, depositing fine particles on top of the grain bed. Or, if your kettle has a ball valve, you can vorlauf on top of the grain.

In either case, you will need to drain the wort out from under the bag into another vessel, at least temporarily. Once the top of the grain bed - with its fine particles - is exposed, you can then pull the bag slowly without getting these bits in the wort.
 
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To each his own but I cannot imagine how a 2-4f loss in 60 minutes means much at all considering that most of the conversion happens in the first 20 minutes or so. I don't wrap my kettle nor turn on the element to warm up the mash and I always hit my target gravity. It is really easy to get caught up in the minutia but that is the beauty of homebrewing, do or worry about what matters to you.

I can see that, but my problem is the temp drops are much bigger. Dough in at 160 and in I'll be at 145 or less in 60 minutes. This resulted in me mashing in a cooler again...and loosing some benefits of BIAB simplicity.
 
I can see that, but my problem is the temp drops are much bigger. Dough in at 160 and in I'll be at 145 or less in 60 minutes. This resulted in me mashing in a cooler again...and loosing some benefits of BIAB simplicity.

I use a bag but mash in a cooler. It may not be as elegant, but it works for me.
 
It is possible to overcome some of the limitations presented above with BIAB but in my case when I did so I didn't see any/enough improvement in the output to warrant doing them regularly.

I have a 3 vessel natural gas herms system where I can control the mash temp with a PID. A few times I've done 10 gallon BIAB batches on this system using just one of the vessels. This allows me to recirculate wort during the mash and adjust temps on the fly to do step or Hochkurz mashes.

I do have a false bottom in the vessel I use for this because it is possible to burn a hole in a BIAB bag applying direct heat to the keggle (ask me how I know).

Recirculating results in clearer wort into the fermenter than if I don't do this but given time and the same clarifiers the resulting beers with or without recirculation end up equally clear and I can't taste a difference.

Whether I am recirculating wort or not I use a double hoist to lift my grain bag as I like to let it stay over the keggle during the boil and drip. My efficiencies doing this with zero sparge are high 70s which I'm fine with.

I wrap my keggle with reflectix (sic) a couple times and never lose more than 2 degrees even if I don't recirculate/reheat during the mash.
 
I can see that, but my problem is the temp drops are much bigger. Dough in at 160 and in I'll be at 145 or less in 60 minutes. This resulted in me mashing in a cooler again...and loosing some benefits of BIAB simplicity.
I guess I am spoiled that I have a climate controlled brew room in my basement so I do not see much temperature loss as opposed to out door or garage brewing. I sometimes forget that.....
 
I can see that, but my problem is the temp drops are much bigger. Dough in at 160 and in I'll be at 145 or less in 60 minutes. This resulted in me mashing in a cooler again...and loosing some benefits of BIAB simplicity.

A lot of guys use Reflectix to insulate their kettles, but I don't think it provides enough insulation, especially to the lid where most heat is lost. I had some old comfortors and blankets laying around and use them. It's not pretty, but it effective. Using 2 blankets folded in half is giving me 4 layers of insulation to my kettle lid. I only drop 2 degrees in a 60 minute mash.
 

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Thanks. That was about what I expected, in short very little on the Disadvantages. Some conventional brewers, using three vessel systems, I know seem to think that Mash Thickness is of great importance on some styles. Why? In my experience it doesn't seem to matter. Of course I really only brew English Ales and German Lagers with a wheat beer thrown in every now and then.
 
biggest disadvantage is flour in your wort. In single vessel it burns on your kettle bottom. Using a mash tun keeps most of it out of kettle if you’re gentle and careful.

recirc and vorlauf can help, but they don’t eliminate it by any means. A cheap igloo mash tun is the easiest way to lessen the impact.
 
I haven't tried it yet, but from what I have read Step Mashing is a bit more complicated with BIAB. You don't want to apply direct heat to the grain bag and adding hot water could easily throw your numbers off. I'm pretty much going to avoid it unless it's absolutely necessary.

I actually step mash every single brew. At least 2 steps before a mashout/batch sparge. It's not 100% perfect, but I've gotten it very close. Basically you just add a measured amount of boiled water and stir. This calc is old, but I still use it: https://www.rackers.org/calcs.shtml

Use the "Rest Calculator" and plug in your numbers. I always round up slightly with how much boiling water I add. If you're doing 10 gallon batches, this may be cumbersome.
 
I actually step mash every single brew. At least 2 steps before a mashout/batch sparge. It's not 100% perfect, but I've gotten it very close. Basically you just add a measured amount of boiled water and stir. This calc is old, but I still use it: https://www.rackers.org/calcs.shtml

Use the "Rest Calculator" and plug in your numbers. I always round up slightly with how much boiling water I add. If you're doing 10 gallon batches, this may be cumbersome.

Dang, now I want to do a step mash. Thanks for the tip. :)
 
biggest disadvantage is flour in your wort. In single vessel it burns on your kettle bottom. Using a mash tun keeps most of it out of kettle if you’re gentle and careful.

recirc and vorlauf can help, but they don’t eliminate it by any means. A cheap igloo mash tun is the easiest way to lessen the impact.
I haven't found this to be true. I boil over propane (Blichmann burner) and don't get burning on the bottom from the flour (and I have a lot.)

Brew on :mug:
 
Dang, now I want to do a step mash. Thanks for the tip. :)

My pleasure! Nothing wrong with single infusions, but I find step mashes give you a lot more control over fermentability, plus things like developing head/body if you're using unmalted grains, etc. etc...

Plus I just like to do more stuff on brewday.
 
I actually step mash every single brew. At least 2 steps before a mashout/batch sparge. It's not 100% perfect, but I've gotten it very close. Basically you just add a measured amount of boiled water and stir. This calc is old, but I still use it: https://www.rackers.org/calcs.shtml

Use the "Rest Calculator" and plug in your numbers. I always round up slightly with how much boiling water I add. If you're doing 10 gallon batches, this may be cumbersome.

Shoot....and I was just about to post that a disadvantage is you can't do step mashes.... :)

Maybe the disadvantage is lesser control. I have a RIMS system, and I don't even care about getting the strike water exactly right, I just bring it up to whatever step temp I want. Never tried step mashing with BIAB, now I wish I had. :)

That said, and it's not much of a criticism of BIAB, I miss the days when I did BIAB. A simpler, faster, more relaxing mode of brewing I cannot imagine. And it is the easiest and fastest and cheapest way to get newbies to all-grain brewing in the game.
 
Definitely better control with a system like that. I'm rarely spot on, but within 2 degrees typically. So I don't usually play with small increases, but something like going from 146 to 155, 158, etc. I messed with it when brewing historical English beers because I saw a lot of mention of "underlet." What I do is not a true underlet, but the same idea. I try to pour down the side of the kettle very gently and stir.

I've been brewing BIAB for almost a decade and see little reason to do otherwise. When I do 10 gallon batches with my brew partner we do a hybrid. Mash in a cooler, but still in a bag.
 
I do a Hochkurz mash every time I brew, direct fire with the grain bag still in. I use a small round stainless backing rack as a false bottom to protect the bag. Never had any problem with scorching of anything. Triple layer of reflectix (melted in several places from forgetting to take it off when I turn on the burner - there's a DISADVANTAGE right there!) on both the sides and the lid keeps my temps pretty stable for each step of my measly 2.5 gal mash.

But that's just my setup and experience. Obviously not the same for everyone.

Burning my hands when I squeeze my grain bag is another stupid disadvantage. My fault for having thin gloves. So, yeah.
 
This past week I brewed a Weizenbock, Dortmunder, and Oktoberfest all using step mashing in a cooler by applying steam. It was a little time consuming but I found it very easy to control temperature. I rigged up a pressure cooker with a shutoff and attached a stainless racking cane with silicone tubing.
 
I haven't found this to be true. I boil over propane (Blichmann burner) and don't get burning on the bottom from the flour (and I have a lot.)

Brew on :mug:
I brew with nat gas (5 and 45gal) and propane(45gal), electric [100]. Happens on all of them.

Whether or not it burns isn’t necessarily the difference. Flour in your wort is no bueno.
 
I brew with nat gas (5 and 45gal) and propane(45gal), electric [100]. Happens on all of them.

Whether or not it burns isn’t necessarily the difference. Flour in your wort is no bueno.
Haven't found flour in the wort to be a problem either. Brewed a 40 point Oktoberfest that was full of flour in the wort.

Brew on :mug:
 
If you're step mashing BIAB by adding boiling water, you're not using a single vessel system anymore, are you?

If you want to get technical, I suppose not, but is it not still BIAB?

I boil water in my electric kettle I use for coffee/tea. I guess if you want to call that a vessel go ahead :)
 
biggest disadvantage is flour in your wort. In single vessel it burns on your kettle bottom. Using a mash tun keeps most of it out of kettle if you’re gentle and careful.

recirc and vorlauf can help, but they don’t eliminate it by any means. A cheap igloo mash tun is the easiest way to lessen the impact.

I haven't found this to be true. I boil over propane (Blichmann burner) and don't get burning on the bottom from the flour (and I have a lot.)

Brew on :mug:

I also don't find this to be an issue. I brew full volume 25L batches on a 3500W induction plate. I was initially going to suggest the induction might be a more even and gentle heating method but I see Doug also doesn't have the issue with his gas burner. Maybe SanPancho has some sort of turbo gas ring?
 
If you're step mashing BIAB by adding boiling water, you're not using a single vessel system anymore, are you?

Technically speaking, you are correct. At this point, however, the reality of BIAB brewing has gone much further beyond the concept of a single vessel and removal of the grains from the wort instead of the traditional wort from the grains. Accept this or not, it is your choice. If it enables people to brew to their liking, then it is all good.
 
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