Squeeze the bag?

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dendron8

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I'm reading up on biab, and most of what I've read says to squeeze the grain bag after you pull it out .

Most references I find on steeping grains say that you should not squeeze the bag.

If I am to put all of my grain into the biab bag, it would include the steeping grains, yes? What is the difference between squeezing the biab bag and squeezing the steeping grains bag?

Thanks!
 
I think at one time squeezing was thought to risk astringency from the extraction of tannins in the grain .. this applied to steeping or biab. That seems to have been dispelled. Lots of people squeeze .. it yields more wort. I prefer to let the bag drain .. if anything, I will set the bag in a colander with something heavy like a panini press on it.
 
Once upon a time (like all fairy tales start), it was thought that squeezing the bag would release tannins from the husks. In reality, if you have your mash pH under 5.9 (preferably in the 5.2 to 5.6 range for best enzyme activity) and the temperature below 170F, tannins are not released from the husks in any great quantity. It would take an immense amount of pressure to force much else from the grains, much more than you can exert with your hands.

The wort you get from squeezing the bag is no different from the wort you already have collected in the pot. I've tried several times to measure a difference, but aside from additional fines, the wort collected from the squeezing has the same pH and specific gravity as what has already drained via gravity.

Steeping is a little different in that you usually have a lot more water for a very little amount of grains. Your pH is uncontrolled and usually for most people on the high side. Though if your temperature is not greater than 170F, it really would not make too much of a difference in my experience.

So, in short, squeeze the bag like it owes you money!
 
Grain is grain. Go ahead and squeeze. The do not squeeze the steeping grain bag is just a left over instruction from when it was thought squeezing would extract tannins.

Rinsing the steeped grains, like a sparge for BIAB, will extract more color and flavor from the grains. Then squeeze.
 
When I BrewedIAB I would squeeze the bag. I never had any off flavors or problems. Get as much of those sugars out as possible.
 
Squeeze that baby!

Baby_9a7bff_1110401.jpg
 
I don't argue with those who squeeze ... BUT .. that bag is hot as hell when it first comes out .. if you used a calculator for h2o volume, you have factored in a certain absorption loss anyway, there are always other things to do while the bag is draining. By all means, squeeze if you like, but don't feel like it is mandatory.
 
I don't argue with those who squeeze ... BUT .. that bag is hot as hell when it first comes out .. if you used a calculator for h2o volume, you have factored in a certain absorption loss anyway, there are always other things to do while the bag is draining. By all means, squeeze if you like, but don't feel like it is mandatory.

So would you advise to let it drip out over a bucket, then dunk it into a bucket with sparge water, and let it drip out again? Or just pour sparge water over the bag, which IMO can't be as efficient as a dunk sparge.

I guess the constraints of the bag and gravity exerts a decent squeeze on the grist if it were to simply hang from a hook or pulley. You don't get that by placing it in a large colander over a bucket.

I don't BIAB. But for reference, the grist in my converted cooler mash tun lauters pretty dry. If I squeezed (or pressed) it I could probably eek another quart of wort out. But after the second sparge, that would be a quart of only 1.016-1.022 wort, at best. I usually let the mash tun drain during the boil and get a quart or so that way. I either add it to the boil later on or boil it down to use for yeast starters.
 
If I can do a full volume mash with biab, there is no sparge step .. just the bag drain. I drain into my old 5G kettle that I got way back in a starter kit as a Xmas gift from the kids. The yield - as you say is about a quart. Let me restate that .. when the bag first comes out, it hangs over the main kettle .. as much as a half gallon my be released. When that is just a trickle, it goes over the small kettle, with a weight on top and I get maybe another quart. The grain at that point is pretty dry. My calc for grain absorption is .05

If my grain bill is over 12 pounds for a 5G batch, I will put a gallon of water in the small kettle and dunk sparge .. bag goes in water, I stir, bag comes up, drains, colander slips under bag and it drains with weight on top. I do not find a huge difference in wort gravity from main kettle to small kettle catching last drainings .. maybe 2 or 3 points
 
Steeping grains are typically steeped in a coarse muslin bag, perhaps squeezing that type of bag passes more particulate.

A proper BIAB bag is preferably polyester voile and is a very fine weave.

I prefer just to let the bag hang over the kettle and drain with gravity, after 30 minutes there is very little left to squeeze.

I feel most of the prolific squeezers are really just impatient, and there really just getting there wort a little sooner than gravity would effortlessly provide given a little time.

If you squeeze the bag a couple minutes after removing from the kettle you get the feeling that your recovering a huge amount of wort, and the squeezing seems so productive satisfying.

But if you let the bag hang and drain for 30 minutes, there's not much left at all to squeeze out. Jme
 
Steeping grains are typically steeped in a coarse muslin bag, perhaps squeezing that type of bag passes more particulate.

A proper BIAB bag is preferably polyester voile and is a very fine weave.

I prefer just to let the bag hang over the kettle and drain with gravity, after 30 minutes there is very little left to squeeze.

I feel most of the prolific squeezers are really just impatient, and there really just getting there wort a little sooner than gravity would effortlessly provide given a little time.

If you squeeze the bag a couple minutes after removing from the kettle you get the feeling that your recovering a huge amount of wort, oh the squeezing seems so productive.

But if you let the bag hang and drain for 30 minutes, not much left at all to squeeze out. Jme

For the most part, this is correct. With the grain bag in a colander, I can squeeze out just a little bit more than I could waiting the 30 to 40 minutes to drip. For me, it takes about 2 to 3 minutes of squeezing after removing the bag with a flat lid that fits inside the colander and the results are very repeatable in terms of water retention in the grains.

During that time, I have a sample of my wort cooling to get a gravity reading (I do full volume BIAB) and the kettle is heating towards boil, so there is really not much time lost.

In the end, it doesn't make too much of a difference hanging vs squeezing and it is more a matter of time and consistent process.
 
Steeping grains are typically steeped in a coarse muslin bag, perhaps squeezing that type of bag passes more particulate.

A proper BIAB bag is preferably polyester voile and is a very fine weave.

I prefer just to let the bag hang over the kettle and drain with gravity, after 30 minutes there is very little left to squeeze.

I feel most of the prolific squeezers are really just impatient, and there really just getting there wort a little sooner than gravity would effortlessly provide given a little time.

If you squeeze the bag a couple minutes after removing from the kettle you get the feeling that your recovering a huge amount of wort, oh the squeezing seems so productive.

But if you let the bag hang and drain for 30 minutes, not much left at all to squeeze out. Jme

I am currently awaiting the delivery of my wilserbrewer "proper" biab bag :)
 
Small batch bag squeezing is likely a little more manageable. I do 15-30 lb grain bills, and it is much easier just to let it hang. When others mention they put their grain bag in a colander to squeeze, I imagine a slightly smaller batch / grain bill that may be easier to squeeze.

With the grain bag in a colander, I can squeeze out just a little bit more than I could waiting the 30 to 40 minutes to drip.

I would be curious to know how much more wort if any would drip out of the grain bag after squeezing right out of the kettle if allowed to drain 30-40 minutes. No matter what I do, there is always a puddle in the barrel that holds the spent grain bag....
 
Here's something I did on my last brew:

I mashed in a bag in a cooler. After draining and sparging, I removed the bag and hung it over the kettle to drain while the wort came up to a boil. I did not squeeze. When it slowed to a drip, I set the bag back in the cooler in preparation for clean-up.

During the boil, I went to dump the grains and discovered an additional cup of wort that had drained into the cooler. I decanted that into a saucepan, boiled it for 30 seconds, cooled it, and poured it into the yeast slurry that I was planning to use with the batch. I shook that up nicely, covered it, and set it aside.

When I was all done with brew day and the wort was ready for yeast, I had a micro-starter with happy yeast already beginning to multiply. Fermentation started up nicely.

So this was a nice way to utilize that last bit of wort and still avoid squeezing, which I find annoying to do.
 
Small batch bag squeezing is likely a little more manageable. I do 15-30 lb grain bills, and it is much easier just to let it hang. When others mention they put their grain bag in a colander to squeeze, I imagine a slightly smaller batch / grain bill that may be easier to squeeze.



I would be curious to know how much more wort if any would drip out of the grain bag after squeezing right out of the kettle if allowed to drain 30-40 minutes. No matter what I do, there is always a puddle in the barrel that holds the spent grain bag....

Easily answered. After squeezing, I put the bag and grains in a bucket to take out to my goats. There is usually a small amount of wort in the bottom after a couple of hours later, though not enough to be able to pour out so probably about 10 to 20 ml total.

When I have allowed the bag to drain for about 40 minutes, I can still squeeze a good 300 to 500 ml from it by pressing. For me, the important thing is that the grain absorption is very consistent, which allows me to easily predict my process.
 
I let it hang and still squeeze the **** out of it to get all the sugars out. So far no issues. Beer comes out great every time. No astringency or anything related to the tannin extraction myth.
 
It seems there's belief among some that squeezing gets you more sugar - gives you a higher pre-boil gravity. But no; what it gets is more volume at the same pre-boil gravity. And yes, mash efficiency takes into account both gravity and volume, so you'll have higher efficiency if you squeeze. But it's just because of the additional volume that you're recovering, not because there is more sugar as a factor by itself.

Therefore, just like including vs. filtering out kettle trub, squeezing the bag is a process choice that you can factor into your recipes. It's not a qualitative choice.
 
I used to squeeze hard but hated the sticky hands and dealing with the hot bag. So now I use a food safe bucket with holes drilled in the base.
After mashing I move the bag to the bucket and suspend above the BK. Sparge in 2-3 steps by pouring water into the bucket and leaving it until it drains. In between sparges I lift the bag for a minute but a pulley would be better if I had one. My efficiency went up considerably and the sparge is done by the time the wort is at a boil. I think squeezing is unnecessary if you allow a bit more time for sparging. But since this happens while the wort heats up it doesn't make brewday any longer.
 
I do 10 gallon batch with an average of 23 pounds of grain. I let it hang above the pot for twenty minutes or so then give a power squeeze or 2 for good measure, probably get a pint maybe 2 from squeezing. Plus it stops and dripping while I transfer to a bucket
 
I'm not at computer right now, but one way to compare would be, for those of us using brewing software, to share what you use for your grain absorbtion calculation.
 
i twist the bag a bit to get most of it out and then i drop it into my old zapap lauter tun and let the rest run out. i usually get about a quart or less.
 
Thanks for all of the great responses. I made a farmouse ale and based on something i read here got a wisler bag and some gloves (amazon) and built this: and squeezed/poured a gallon of 170 degree water over/squeezed again. my efficiency and OG were spot on.
 
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Thanks for all of the great responses. I made a farmouse ale and based on something i read here got a wisler bag and some gloves (amazon) and built this: Derrick and squeezed/poured a gallon of 170 degree water over/squeezed again. my efficiency and OG were spot on.

Not a thing wrong with that, and will all love our Wilser bags! In your Alton Brown setup, be careful you secure the bag's rope line so it doesn't get away from you. Splash into hot wort, burns dendron8, makes mess. Wilser also has available a ratchet pulley that secures the free line for you. Way to go and enjoy the simplicity of BIAB.
 
Steeping grains are typically steeped in a coarse muslin bag, perhaps squeezing that type of bag passes more particulate.

A proper BIAB bag is preferably polyester voile and is a very fine weave.

I prefer just to let the bag hang over the kettle and drain with gravity, after 30 minutes there is very little left to squeeze.

I feel most of the prolific squeezers are really just impatient, and there really just getting there wort a little sooner than gravity would effortlessly provide given a little time.

If you squeeze the bag a couple minutes after removing from the kettle you get the feeling that your recovering a huge amount of wort, and the squeezing seems so productive satisfying.

But if you let the bag hang and drain for 30 minutes, there's not much left at all to squeeze out. Jme

You hit the nail on the head. I squeeze but I have burnt my hands doing it because I don't have the patience to wait for it to cool down before I start my boil. I brew 2.5 gallons and don't have a massive bag of grain and I do it in the kitchen so no pulley system either. It's just me holding a bag over a pot in the end and my arms tire out after a while.

When I started BIAB, I aimed for 65% efficiency and just about hit that each time without squeezing but now that I squeeze, coupled with constant recirculation during mash, I hit 75%+ every time now. I should buy some Kevlar gloves maybe.
 
Last few times I let the bag hang for about 10 or 15 mins and then just grabbed the bag by the "neck" and twisted a little, like wringing a mop.

Was pretty easy and I didn't have to fool around with hot grains or sticky "wort hands"
 
Last batch I plopped the grain bag in a stock pot/spaghetti strainer, and squeezed it, pressed it, punched it, whacked it with a large (star san sprayed) storage jar full of rice, etc.

Yes - it was hot at first, so be careful.

If you're doing a small stove-top batch like I did (10 L in the primary), you want all the volume of wort you can get!
 
We bought 2 pair of silicon gloves and one guy holds the top of the bag and the other twists it and squeezes the heck out of it. We have been doing that method for a while and finally ordered the gloves. Much less pain and more wort with the gloves.
 
Another reason recipe kits might suggest not to squeeze is that makes it harder for them to predict what your final product will taste like, as everyone squeezes differently. Removing that variable just makes it easier on them.
 
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