BIAB compared to not

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Hi community,
I recently did a second hefeweizen brew with the only difference between the two being BIAB method compared to not, or standard and I got a significantly lower OG of 1.038 compared to first 1.048. What happened here.? Same everything. Same wheat/Pilsner batch as the first. What happened?
 

hotbeer

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Do several more batches of the same recipe and average the results for each method.

However, I might just suspect it's how you do or don't rinse your grains. If you just pull your bag and let it drip, then you might be leaving sugars in the bag. I rinse or sparge my bag with clean water which gets added to the first running's from the bag.
 
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Thanks for quick replies.

12l wort
15min at 47C
25min at 67C
40min at 72C
Mash out at 78C. Keep for 5 min
Sparge water 16l at 78C
Boil for 60 min. Hops in at start of boil.
Cool to 25 C and add yeast.
Wheat malt 2.5kg, Pilsner malt 1.5kg, Caramel malt 0.2kg

Stirring every few minutes.
When BIAB, I sparged water through the grain bag.
Thanks
 

marc1

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Thanks for quick replies.

12l wort
15min at 47C
25min at 67C
40min at 72C
Mash out at 78C. Keep for 5 min
Sparge water 16l at 78C
Boil for 60 min. Hops in at start of boil.
Cool to 25 C and add yeast.
Wheat malt 2.5kg, Pilsner malt 1.5kg, Caramel malt 0.2kg

Stirring every few minutes.
When BIAB, I sparged water through the grain bag.
Thanks

Was you bag at least as big as your mash tun?

I'd try for equal water for the mash.

Also, the pour through the bag sparge may not be as efficient; try putting the bag in a bucket or pot and adding the water there, then stirring, let it sit a couple minutes, and then pulling the bag.
 

jtgoral

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I made over 150 BIABs and I am getting OG within +/-0.002 compared to one calculated by BeerSmith software. I use 8.25 gallon of water to get ~5.75 gallon of wort I pitch. I just lift the bag and let it drain. The water drips from the bag for over 30 minutes most of the time. This is into the middle of the boiling. No sparging, no additional water.
 
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Thanks. Can the bag mesh size have an impact. I have a 75micron bag which is plenty fine and not letting anything but liquids through. It took forever for liquid to run through and I ended up squeezing the wort after about 10min of dripping. Is the extreme restriction bad? Should I not have some particles come through? For the non BIAB I just strained through a cheese cloth and then through a "standard" hose filter to capture any solids before bottling.
 

gencinjay

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I recently started using a bag in my process. I mainly started so that I could do a finer crush and not clog up my system. I have since discovered that I also need a bit more water in the mash to hit my targets.
 
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Boil in bag was also to have clean transfer and less particles in final wort but I saw little benefit. Can just pour everything through bag before going to fermenter
 

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Is your kettle big enough for a full volume mash? You have BIAB brewed using "conventional" 3V parameters. Some will argue, but the benefit of BIAB is using full volume and not requiring a separate sparge. You clearly did not get the lautering efficiency.

While that is a very fine mesh, I doubt it had much impact on holding back the sugars; it just impacts the time to drain.
 
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Yes I can do a full volume mash but trying to follow recipe with sparge water. Using smaller kettle and maintaining heat was easier. Anyways something clearly caused og to drop so much and still not sure. Movement of liquid through fibre mesh bag was maybe inhibited even though I was stirring every few minutes.
 

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15min at 47C
25min at 67C
40min at 72C
Mash out at 78C. Keep for 5 min
Stirring every few minutes.
Since your mash is much thicker than just water, the heat you add doesn't circulate and it is really easy to get the bottom of the mash too hot and denature the enzymes. Stirring every few minutes isn't enough, you need to be stirring constantly and vigorously during the times you add heat for your steps. Once the enzymes are denatured you can't get them back.
 

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Yes I can do a full volume mash but trying to follow recipe with sparge water. Using smaller kettle and maintaining heat was easier. Anyways something clearly caused og to drop so much and still not sure. Movement of liquid through fibre mesh bag was maybe inhibited even though I was stirring every few minutes.
How small a kettle compared to the amount of grain you used? I'm sure some probably do different, but I like to have enough room for the bag for the grain inside to move around easily as I stir it.

If you have it all bound up tight then water isn't going to circulate well through the grain and pick up the sugars it should.

Similarly when you sparge it, if it's a tightly packed bundle, then the water will find the quickest and easiest path out of the bag and miss most of the grain.

I don't think what I do would actually be considered a sparge. I simply dunk the bag in another pot of water and stir the grain around in the water again, then remove the bag to drain.
 
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Since your mash is much thicker than just water, the heat you add doesn't circulate and it is really easy to get the bottom of the mash too hot and denature the enzymes. Stirring every few minutes isn't enough, you need to be stirring constantly and vigorously during the times you add heat for your steps. Once the enzymes are denatured you can't get them back.
That actually makes sense as it is difficult to stir inside a bag even though I tried. I think I will use bag only to do final transfer
 

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Well if the bag is sized to the pot and you don't have enough room to stir the grain, then perhaps the pot is too small, or you simply aren't using enough volume of mash water to let the grain disperse evenly.

The kit's I started with suggested mashing was like making oatmeal for breakfast. However if I mashed to the thick consistency I liked my oatmeal to be, then there wouldn't be any mash water to even drain from the bag.
 
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How small a kettle compared to the amount of grain you used? I'm sure some probably do different, but I like to have enough room for the bag for the grain inside to move around easily as I stir it.

If you have it all bound up tight then water isn't going to circulate well through the grain and pick up the sugars it should.

Similarly when you sparge it, if it's a tightly packed bundle, then the water will find the quickest and easiest path out of the bag and miss most of the grain.

I don't think what I do would actually be considered a sparge. I simply dunk the bag in another pot of water and stir the grain around in the water again, then remove the bag to drain.
Well the small kettle is just big enough
Well if the bag is sized to the pot and you don't have enough room to stir the grain, then perhaps the pot is too small, or you simply aren't using enough volume of mash water to let the grain disperse evenly.

The kit's I started with suggested mashing was like making oatmeal for breakfast. However if I mashed to the thick consistency I liked my oatmeal to be, then there wouldn't be any mash water to even drain from the bag.
I think the pot is big enough for everything as it didn't seem constrained with all the headroom. With bag material getting in the way of natural mixing due to water heating up it could cause things not to mix as desired. BIAB is suppose to ease cleanup but if I spend all the time in additional mixing, then I don't see the point.
 

marc1

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Well the small kettle is just big enough
I think the pot is big enough for everything as it didn't seem constrained with all the headroom. With bag material getting in the way of natural mixing due to water heating up it could cause things not to mix as desired. BIAB is suppose to ease cleanup but if I spend all the time in additional mixing, then I don't see the point.

If the bag is getting in the way of mixing it sounds like it's too small.

So make it less complicated.

Make sure your bag is at least as big as your pot (your pot should be able to fit inside the bag).

If you want to sparge, put about half your water in the kettle, add your grain, stir well, cover it and wrap with insulation like a sleeping bag to keep it warm. Open it at 30 minutes to stir if you want.

After an hour or so, pull the bag, drain it, and put it in a big bucket or another pot. Add the rest of your water to the grain (room temp works fine) and stir well. Give it a few minutes then pull the bag and drain that.

Or, mash as above with all your water and skip the sparge. You'll probably lose a little efficiency but gain convenience.

Don't heat while mashing.

If you need to have a complicated step mash, do it by adding boiling water and stirring in, not by bottom heating.
 
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If the bag is getting in the way of mixing it sounds like it's too small.

So make it less complicated.

Make sure your bag is at least as big as your pot (your pot should be able to fit inside the bag).

If you want to sparge, put about half your water in the kettle, add your grain, stir well, cover it and wrap with insulation like a sleeping bag to keep it warm. Open it at 30 minutes to stir if you want.

After an hour or so, pull the bag, drain it, and put it in a big bucket or another pot. Add the rest of your water to the grain (room temp works fine) and stir well. Give it a few minutes then pull the bag and drain that.

Or, mash as above with all your water and skip the sparge. You'll probably lose a little efficiency but gain convenience.

Don't heat while mashing.

If you need to have a complicated step mash, do it by adding boiling water and stirring in, not by bottom heating.
Very interesting. Somewhat different from other styles. Mixing all the time to mixing pretty much never. Also room temp sparge? And adding boiling water rather than heating normally? .. All the more factors to consider
 

hotbeer

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BIAB is suppose to ease cleanup
BIAB is different things to different people. But that's a first to me that it's supposed to be easy to clean up.

BIAB also has quite a few various ways people go about doing it and what they use. Just like there are even more ways to make beer.

If your bag was getting in your way, then you have to figure out why that is. Some people have the bag open and stir in the bag itself. If the open part of the bag is in your way, then roll it over the sides of your pot. I use a bag that I can close up all the way and fits inside my pot completely. I just push it around and squeeze it occasionally while in the water. The bag is large enough so that the grain is always loose in it.

While you might be able to just mash and pour your mash through the bag to strain it, you might find that just results in a bag full of mash that won't drain because it got plugged up with all the gummy proteins and other leftover material.

If I was just going to strain it, I wouldn't use a bag. I'd just do a conventional mash and sparge. And I have actually done so several times. In some ways it's actually less trouble. But more than not I use a bag.
 

marc1

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Very interesting. Somewhat different from other styles. Mixing all the time to mixing pretty much never. Also room temp sparge? And adding boiling water rather than heating normally? .. All the more factors to consider

How were you doing a step mash in your non-BIAB version? Heating the cooler MLT? Were you stirring your non-BIAB batch the whole time?

I guess I don't understand what you are comparing here. What's your non-BIAB process? What are you trying to get out of this?

There's a ton of different ways to run your process, no matter which method you are using.

I like BIAB a lot, but not everyone does. It's different, and might not be for you. But it's hard to tell if you just need some tweaks to make it better for you, and you'll love it, or if you'll always prefer the "traditional" method, however you are doing it.
 

Beermeister32

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I usually use what I call DBIAB - Double Brew in a Bag. Uses two bags to keep the weight down, simplifies extraction and rinsing of the bags.

69F0612A-0087-48A8-B12F-C1736ADB7F78.jpeg
 

RM-MN

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That actually makes sense as it is difficult to stir inside a bag even though I tried. I think I will use bag only to do final transfer
Maybe try BIAB without the steps in your mash. People have reported that they can't tell the difference in the final product.
 
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Hi. Returning to the topic. I skipped the brew in bag completely and just brewed straight in kettle. I also then sparged before mash out and then chucked the entire batch through the mesh bag. I think it worked pretty well. Taste will tell. Rather a lot of hops came through another filter basket i used and is currently in the fermenter before yeast introduction. I was wondering if I can leave this hops during fermentation process or if this is going to give off bad flavours. Rather strain it again? Advice?
 
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I usually use what I call DBIAB - Double Brew in a Bag. Uses two bags to keep the weight down, simplifies extraction and rinsing of the bags.

View attachment 747697
Great idea. I was struggling with my bag as it ended up weighing a tonne. I didn't brew in it as the mesh is too fine and restricts flow of water but I used it as a filter bag, trying to not spill or burn myself in the process.
 
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Maybe try BIAB without the steps in your mash. People have reported that they can't tell the difference in the final product.
Do you mean straight to final temp before mash out and keep it there for an hour or so?
 

marc1

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Hi. Returning to the topic. I skipped the brew in bag completely and just brewed straight in kettle. I also then sparged before mash out and then chucked the entire batch through the mesh bag. I think it worked pretty well. Taste will tell. Rather a lot of hops came through another filter basket i used and is currently in the fermenter before yeast introduction. I was wondering if I can leave this hops during fermentation process or if this is going to give off bad flavours. Rather strain it again? Advice?

How did you sparge? Did you pour your mash out through the grain bag into another container, then dumped the grain back into the kettle and added the sparge?
 

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Rather a lot of hops came through another filter basket i used and is currently in the fermenter before yeast introduction. I was wondering if I can leave this hops during fermentation process or if this is going to give off bad flavours. Rather strain it again? Advice?
I wouldn't worry about it. If you were to dry hop by adding hops directly to the fermenter then the current hops from the boil will only be in there 3 to 7 days longer. And all will just become trub on the bottom of the fermenter.

If you can recognize a taste in the final product that points to the hops as a possible culprit, then you can plan for how to deal with them for the next batch and not something you have to conjure up at the spur of the moment.
 

jdauria

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Definitely a finer crush with a bag vs without,, squeeze the bag when draining and a no-sparge full volume mash would probably get you a lot closer to the "normal" brew OG.
 
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Definitely a finer crush with a bag vs without,, squeeze the bag when draining and a no-sparge full volume mash would probably get you a lot closer to the "normal" brew OG.
Thanks, I have now encoutered the same issue with two batches. Latest big batch I did as normal, with step mash without bag and it gave me 1.038 OG out and thats with sparging 78C water through mash bag back into pot for boiling and hops addition. I proceeded to squeeze out as much wort as I could. No loose liquid remains afterwards but still such a low OG. The only difference between my methods is the bag mesh size. First big batch I poured everything through double layers cheese cloth bag and got OG 1.046. Second batch poured everything through 200mesh (75micron) mash bag and got OG of 1.038. Surely I must be trapping some of the undesolved sugars. I wouldn't expect that but data is data.
 

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I run my grain though the mill twice and use about 2/3 of the water in the mash and 1/3 for a dunk sparge in a side pot. Only stir at the beginning and end of the mash and then during the dunk sparge.
Almost always hit my expected numbers using this method. I'm going to start double bagging for large batches and higher ABV small batches, thanks Beermeister32.
 
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In my opinion if sugars inside the bag are higher value than sugars outside the bag, then one of two things is happening ... 1) you are not stirring enough to equalize the value of the wort throughout the vessel, or 2) you are not mashing long enough to allow the full release of sugars from the grain. Just my opinion.
 

jdauria

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Thanks, I have now encoutered the same issue with two batches. Latest big batch I did as normal, with step mash without bag and it gave me 1.038 OG out and thats with sparging 78C water through mash bag back into pot for boiling and hops addition. I proceeded to squeeze out as much wort as I could. No loose liquid remains afterwards but still such a low OG. The only difference between my methods is the bag mesh size. First big batch I poured everything through double layers cheese cloth bag and got OG 1.046. Second batch poured everything through 200mesh (75micron) mash bag and got OG of 1.038. Surely I must be trapping some of the undesolved sugars. I wouldn't expect that but data is data.

Hmm...75 micron bag, it could be trapping sugars. There are two sites that sell great brew bags, brewinbag.com and biabbags.webs.com. They sell 200 micron bags. The larger the micron the more liquid/sugar can get through. I have used bags from both companies when I was BIAB brewer and they are great. Now because I use an Anvil Foundry, I use a 400 micron bag which is recommended when using recirculation. Both of those companies sell bags customized for your kettle size. I recommend trying one of them. They are great bags and last a long time. The cheap bags sold at homebrew shops or on Amazon just don't cut it.
 
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