MIAB - Sparge or Squeeze?

[vallonswayla]

I plan on mashing in a cooler, and wanted feedback on squeezing the bejesus out of the bag vs. draining the cooler and then sparging to get the pre-boil volume I'm looking for into the kettle.

 

[bgmac]

You could do both. My usual process is to sparge with hot water and let the bag drip dry over the boil kettle for a long time. Then give it a final squeeze before moving away. A hot sparge (like 168f) will help wash out all of those sugars trapped in the grain bed.

 

[Hwk-I-St8]

I've used that same process. I squeezed first runnings, then did a batch sparge and squeezed those second runnings too.

 

[vallonswayla]

Slap and tickle?

 

[LittleRiver]

I plan on mashing in a cooler, and wanted feedback on squeezing the bejesus out of the bag vs. draining the cooler and then sparging to get the pre-boil volume I'm looking for into the kettle.

You will always get a bit better efficiency with a sparge. The question is do you need that extra efficiency, and is it worth the effort?

You can completely eliminate squeezing and sparging, and still have great efficiency, if you crush very fine (~.025") and let the bag fully drain by gravity.

That's a very effective and efficient way to go if you're doing BIAB single vessel (using only a kettle), and you have an overhead hoist point for the bag. Mash with full water volume and insulate the kettle. When the mash is done, remove the insulation, hoist the bag, and immediately fire the heat for the boil. The bag drains into the kettle during the entire boil. That's what I do, and get BH efficiency in the low 80's. There's never a need to transfer hot liquid. It's so easy and effective it's almost like cheating.

If you're mashing in a cooler, and your grains are coarsely crushed, do a sparge.

 

[doug293cz]

Squeezing and sparging both improve lauter efficiency. If you combine them, you get an even larger efficiency improvement. Squeezing reduces the grain absorption rate, which reduces the amount of sugar left behind in the grain, thus improving lauter efficiency. Sparging rinses most of the sugar left in the grain after the previous run-off step, thus increasing lauter efficiency, But, neither sparging, nor squeezing can get all of the residual sugar out of the spent grain, so lauter efficiency will always be less than 100%. Conversion efficiency can reach 100%, but is often less, especially with coarser grain crushes. Mash efficiency equals conversion efficiency times lauter efficiency, so mash efficiency will always be less than or equal to lauter efficiency.

The chart below shows the effect on lauter efficiency of different numbers of batch sparges, and for two different grain absorption rates. 0.12 gal/lb is typical for a simply drained mash tun, and 0.06 gal/lb is a value achievable with a good squeeze. The chart assumes the same level of squeezing for both initial run-off and all sparges. If you only want to squeeze once, do it after the initial run-off (before sparging), as this will get better lauter efficiency than squeezing after sparging. Fly sparging, if done well can achieve better lauter efficiency than a 3X batch sparge at 0.12 gal/lb grain absorption.

Brew on

 

[LittleRiver]

If there is no way to let gravity & time fully drain the bag, squeezing makes sense. There's a lot of liquid still in the bag, it's worth the effort.

If you can let gravity & time fully drain the bag, squeezing doesn't make a lot of sense. You can gain maybe an additional cup or so of liquid by squeezing a fully drained bag. To me, that small amount is not worth the effort.

 

[downzero]

I can say that squeezing is definitely worth it. I've measured the gravity of the wort from squeezing and it was higher than the gravity of the wort in the brew kettle at the time.

 

[Oginme]

I plan on mashing in a cooler, and wanted feedback on squeezing the bejesus out of the bag vs. draining the cooler and then sparging to get the pre-boil volume I'm looking for into the kettle.

The answer is "what do you want to do?" There is no correct or incorrect way to run your process; there is only how you want to work the process. If you keep track of your volumes in and out, you can quickly determine the amount of water which is left in your grains as a function of the weight of the grains, the amount collected from your first runnings, sparge (if you perform one), and bag compression (if you perform one) to be able to estimate what you volumes need for future brews to attain your target pre-boil volume.

 

[odie]

I don't think you can really get 100% of the sugars out unless you repeatedly sparge. But then you are left with an excessive volume of diluted wort that you will have to boil down for a long time.

With a full volume BIAB mash, the ratio of sugar to volume is less than a traditional 3V mash tun. So that the remaining liquid in the grain sack after draining and squeezing is doesn't really hold that much total sugar from the grain bill. Your mash is diluted so that liquid that is retained in the grain holds a lower concentration of sugar. With letting the bag drain over the kettle the entire boil and a few good squeezes, you pretty much get all the sugar you are gonna get from a regular 3V sparge I would think.

With sparging you have to mash with a lesser volume so that the sugar concentration is higher, thus the grain retains more of the potential sugars, which is then mostly recovered during the sparging process.

I think either method will net you basically the same amount of potential sugars in the kettle. There will always be residual sugar left in the grain unless you want to sparge endlessly and boil down endlessly. You quickly reach a point of diminishing returns.

Either full volume mash or go 3V...

I guess a big question is which method delivers better conversion? Is 100% conversion possible with either or both methods? I don't mean extraction of the sugar to the kettle but converting all the starches to fermentable sugar. A sparge will eventually wash all the converted sugars out. But will a 3V mash convert 100% of the starch? The benefit of the full volume mash is "improved" conversion of starches, or so I thought?

Which is better? 100% sparge of a 90% conversion or a 90% BIAB squeeze of 100% conversion?

 

[vallonswayla]

I'm not aiming for max efficiency, I'm more after max easiness. My preference would be to drain the cooler and then pour another half gallon or so of water in, stir a bit and then drain and be done with it. Not really interested in hoisting a bag of wet grains and squeezing so would prefer to avoid that process.

 

[LittleRiver]

... I'm more after max easiness.... Not really interested in hoisting a bag of wet grains and squeezing so would prefer to avoid that process.

If you do indeed want maximum easiness, ditch the cooler and set up a hoist point above your kettle from which you can lift and hang the bag. Let it drip into the kettle during the entire boil. If you do that there will be no need to squeeze it.

This is not the only way to conduct a mash, but it IS the easiest way with the easiest clean up afterward.

For more easiness, ditch the sparge. If you crush your grains fine (.025") you can get BH efficiency in the low 80's without sparging, without squeezing. I do it all the time.

 

[Steven Barrett]

Anecdotally, I've noticed the wort that comes out of the squeezed bag is very cloudy - my guess is this is the grain flour being pushed through the mesh. Has anyone else noticed this? This seems to go against the MLT process recommendation of "sparge until wort runs clear."

 

[doug293cz]

Anecdotally, I've noticed the wort that comes out of the squeezed bag is very cloudy - my guess is this is the grain flour being pushed through the mesh. Has anyone else noticed this? This seems to go against the MLT process recommendation of "sparge until wort runs clear."

Yes, squeezing will also push flour out of the grain mass, as well as wort. This will all settle out with the rest of the trub, either at the bottom of the BK or fermenter. The resulting beer can be just as clear as if you started with clear wort after lautering. Clarity of the wort in the BK has no correlation to the clarity of the finished beer.

Some people find clear wort flowing into the BK more aesthetically pleasing, and that's ok if that's what they care about. There are others that will argue that the extra lipids, etc. in cloudy wort will have some detrimental effect on the flavor or stability of the finished beer. I haven't seen any compelling evidence for the latter.

Brew on

 

[RM-MN]

This seems to go against the MLT process recommendation of "sparge until wort runs clear."

That's been a change that has happened over the years. The original probably was to recirculate until the grain particles coming out are a small enough amount to satisfy the brewer as one doesn't really want the grain in the boil.

 

[doug293cz]

... as one doesn't really want the grain in the boil.

Unless you are doing a decoction.

Brew on

 

[Steven Barrett]

There are others that will argue that the extra lipids, etc. in cloudy wort will have some detrimental effect on the flavor or stability of the finished beer. I haven't seen any compelling evidence for the latter.

There's a Journal of the Institute of Brewing article on flavor stability with respect to wort clarity, hot-side oxygen reduction, and avoiding excessive temperatures: TECHNOLOGICAL FACTORS OF FLAVOUR STABILITY

 

[FlabbyRoach]

I’ve been doing BIAB for going on five years now and i let the bag drain until I put my immersion chiller in. Once that’s in I take the hanging bag and put it in a 5 gallon bucket. There it sits until I do my clean up.
Last batch was 13 pounds of grain mashed for an hour
after sitting for about 20 minutes or so I pull the bag out of the bucket and dump the grain out in my garden
I usually have less than 8 ounces of liquid left in the bucket and I never touch the bag.
i guess I’m just lazy but I got into BIAB brewing for the utter simplicity of it while it makes great quality beer
one bag, one kettle, one fermenter, fine crush
simple

 

[wsmith1625]

If you're mashing in a cooler, you should definitely vorlauf to clear up your wort. That's my biggest complaint about BIAB is all the hot break due to the fine crush.

To answer your question, don't squeeze the bag. It's extra work and it's messy, plus you don't need it. And sparge only if you find your efficiency is too low or that you can't mash full volume.

If your efficiency is low, you can adjust your crush or use more grain. There are many options, just matters what you want to do. I like the simplicity of BIAB so I don't use a cooler, don't sparge, and don't squeeze.

 

[Steven Barrett]

@FlabbyRoach and @wsmith1625 do you feel your process results in clear wort?

 

[wsmith1625]

Hi Steven. I have clear wort, but so much cold break that I end up taking more of it into the fermenter than I would like. I always use 1/2 a whirflock tablet in the last 15 minutes of the boil, then I quickly chill with an immersion chiller, do a manual whirlpool with my SS spoon, and let it sit for 30 minutes before I transfer. The initial flow to the fermenter is crystal clear, but when I get to 4 gallon mark, I start pulling cold break. I think it's because I crush so fine and get flour. I also use a Wilser bag, so I know the bag is not the problem.

I think I could benefit from a vorlauf, but I'm not willing to add it to my process. My beer comes out fine, the cold break settles out in the primary.

 

[Toxxyc]

Alright, so what I do (I haven't read the thread completely) but I've done this over a few batches now with some great results. My efficiency sticks between 77% and 80% for the most part, but I've had 85% with a different recipe before. Anyway, what I do is simple:

1. Mash in bag in little water (relatively thick mash).
2. Squeeze the crap out of the bag. I put the bag in a colander over the kettle and let the wort drip down until it slows down, then I squeeze. In fact, I compress the bag. I put the colander in a big bowl, and squeeze from the top with another big bowl. This forces out a lot of wort, and leave the grain bag pretty dry.
3. Then I dunk the grain bag in a different container with very hot water. Like, 175°F or thereabouts. There's also a lot of water, and it's here where I make up my boil volume. I then stir the crap out of the grains in the bag as well to "wash" the malts properly, and let it sit for another 20 minutes or so.
4. After the wait, I again lift out the bag, spin it a bit to "squeeze" that way, in the colander and the colander is placed over the wort again. Wait until it stops dripping and then I do the two-bowl squeeze again.

This process gets me a pretty good efficiency. I have to add I've got a pleb palate, so it's very possible that I'm not picking up astringency or whatever you get from doing the squeeze thing, but my beers are good enough for me.

I also enjoy the efficiency. It's great. Without squeezing TOO much, I've had a consistent 77% efficiency for the past 5 identical brews I did, so it's a nice and predictable process at this stage.

EDIT: My wort is cloudy as hell, and I don't use kettle finings in my boil. I do no-chill cubing and end up pitching everything into the fermenter anyway. I'll be able to give updates on the clarity once I've done some more testing with it personally, and I'm thinking it's a great idea to do one with Irish moss and one without, then ferment them both and do a comparison sans gelatin with both, side-by-side. I've got two vessels, maybe a small-batch test is in order...

 

[ChiknNutz]

I haven't yet done BIAB, but plan to for my next brew. This is how I plan to go about it.

 

[wsmith1625]

Alright, so what I do (I haven't read the thread completely) but I've done this over a few batches now with some great results. My efficiency sticks between 77% and 80% for the most part, but I've had 85% with a different recipe before. Anyway, what I do is simple:

1. Mash in bag in little water (relatively thick mash).
2. Squeeze the crap out of the bag. I put the bag in a colander over the kettle and let the wort drip down until it slows down, then I squeeze. In fact, I compress the bag. I put the colander in a big bowl, and squeeze from the top with another big bowl. This forces out a lot of wort, and leave the grain bag pretty dry.
3. Then I dunk the grain bag in a different container with very hot water. Like, 175°F or thereabouts. There's also a lot of water, and it's here where I make up my boil volume. I then stir the crap out of the grains in the bag as well to "wash" the malts properly, and let it sit for another 20 minutes or so.
4. After the wait, I again lift out the bag, spin it a bit to "squeeze" that way, in the colander and the colander is placed over the wort again. Wait until it stops dripping and then I do the two-bowl squeeze again.

This process gets me a pretty good efficiency. I have to add I've got a pleb palate, so it's very possible that I'm not picking up astringency or whatever you get from doing the squeeze thing, but my beers are good enough for me.

I also enjoy the efficiency. It's great. Without squeezing TOO much, I've had a consistent 77% efficiency for the past 5 identical brews I did, so it's a nice and predictable process at this stage.

EDIT: My wort is cloudy as hell, and I don't use kettle finings in my boil. I do no-chill cubing and end up pitching everything into the fermenter anyway. I'll be able to give updates on the clarity once I've done some more testing with it personally, and I'm thinking it's a great idea to do one with Irish moss and one without, then ferment them both and do a comparison sans gelatin with both, side-by-side. I've got two vessels, maybe a small-batch test is in order...

There are a lot of side by side tests that have been done already if you care to read them. Brulosophy has quite a few.

Squeeze vs. No Squeeze
http://brulosophy.com/2017/05/22/br...ag-has-on-beer-character-exbeeriment-results/
Whirflock vs. No Whirflock
http://brulosophy.com/2017/03/27/the-whirlfloc-effect-exbeeriment-results/

 

[RM-MN]

different container with very hot water. Like, 175°F or thereabouts

You'll get approximately the same results from your sparge if you use cool water plus you get the benefit that the cool water doesn't extract tannins. It probably won't cause tannin extraction anyway because it takes a high pH plus water over 170F to do so.

so it's very possible that I'm not picking up astringency

You aren't picking up the astringency because there is none. You cannot squeeze hard enough to extract tannins. See above.

 

[balrog]

Max ease = drain while heating. That's it. Do the same thing every time and you will know what to expect every time, regardless of efficiency obtained. You want to chase higher efficiency, then you will exchange some ease for that. It's up to you.

 

[Steven Barrett]

Bag squeezers, do you wear gloves to not burn your hands? 152 deg F is hot!

 

[balrog]

I bought some of them silicone bbq gloves back when I tried squeezing before I eliminated that step for ease. They do work well. Example

 

[wsmith1625]

I haven't yet done BIAB, but plan to for my next brew. This is how I plan to go about it.

I watched the video and his process is really good. If you want to do BIAB, you definitely need a pulley or some other rig to support the bag when you lift it from the kettle. I don't know where he got his insulation, but I use 2 old comforters folded in half (4 layers) to insulate and my temp loss is the same as his. Make sure you insulate your lid as most heat it lost there. Also, don't check temperature mid mash as it will just allow heat to escape. As I'm sure you know already, the squeeze is the only step that is optional. A lot do it and a lot don't. I don't. When you see him putting on his gloves, that's when I start heating to a boil. Leave the bag hanging until it's done draining. Up to you and I don't think it really makes a difference in the final product. Good luck!

 

[ChiknNutz]

I watched the video and his process is really good. If you want to do BIAB, you definitely need a pulley or some other rig to support the bag when you lift it from the kettle. I don't know where he got his insulation, but I use 2 old comforters folded in half (4 layers) to insulate and my temp loss is the same as his. Make sure you insulate your lid as most heat it lost there. Also, don't check temperature mid mash as it will just allow heat to escape. As I'm sure you know already, the squeeze is the only step that is optional. A lot do it and a lot don't. I don't. When you see him putting on his gloves, that's when I start heating to a boil. Leave the bag hanging until it's done draining. Up to you and I don't think it really makes a difference in the final product. Good luck!

Thanks for the feedback. I have the pulleys (got the set from wilserbrewer) and also picked up some insulated gloves like shown. As this will be my first BIAB, figured I'd try it this way and see how it goes, can always amend the process next time. Still have to decide WHAT to make. Want to make a batch of Irish Death as I can't get it here in NC (it's local to WA state) but that is a complex grain bill, might try a simple SMaSH recipe just to have a better chance of success.

 

[balrog]

Temp is only important really during conversion and with fine crush for BIAB that can happen fairly quickly. With a 7-9 gallon thermal mass, temp simply will not drop much. My point is that holding accurate temp for an hour is very likely unnecessary (see, for instance many posts by @RM-MN ).

 

[wsmith1625]

Thanks for the feedback. I have the pulleys (got the set from wilserbrewer) and also picked up some insulated gloves like shown. As this will be my first BIAB, figured I'd try it this way and see how it goes, can always amend the process next time. Still have to decide WHAT to make. Want to make a batch of Irish Death as I can't get it here in NC (it's local to WA state) but that is a complex grain bill, might try a simple SMaSH recipe just to have a better chance of success.

I'm not sure your grain bill matters much to the BIAB process, but a simple recipe will allow you to focus on process. I did a basic pale ale my first batch and it turned out great. I learned a lot from that brew. I thought I had everything spot on and my efficiency was still low. I bought a grain mill for the next batch and then I overshot target gravity. I'm still fine tuning my process and learning more each brew. Beers have been delicious.

 

[ChiknNutz]

I'm not sure your grain bill matters much to the BIAB process, but a simple recipe will allow you to focus on process. I did a basic pale ale my first batch and it turned out great. I learned a lot from that brew. I thought I had everything spot on and my efficiency was still low. I bought a grain mill for the next batch and then I overshot target gravity. I'm still fine tuning my process and learning more each brew. Beers have been delicious.

Understood. Just meant that I might not want to try a complex brew for my first all-grain BIAB, should keep it simple for the first one me thinks

 

[bleme]

Bag squeezers, do you wear gloves to not burn your hands? 152 deg F is hot!

No gloves. Squeeze through the pain then run cold water over my hands.
The more I do it, the less I feel it.

Like @Hwk-I-St8 , I squeeze, sparge, squeeze and usually get efficiency in the 90's.

Although my last beer I decided to just do a full-volume mash and minimal squeeze. That was kinda nice....

 

[FlabbyRoach]

@FlabbyRoach and @wsmith1625 do you feel your process results in clear wort?

Steve,
Yes, I think it results in very clear wort but I do use a half tab of Wirfloc when i put my immersion chiller in the last 15 minutes.

 

[RM-MN]

I mill the grain really fine then at the end of the mash I squeeze, sparge, squeeze, sparge, squeeze, and do a final sparge. My wort is really milky with all the flour that comes through but....

I don't drink wort, I wait until it is beer. The beer is clear, so what do I care what the wort looks like.

 

[balrog]

I did not realize you double rinsed.

 

[RM-MN]

I did not realize you double rinsed.

Um, I triple sparge. My kettle is a bit small and by sparging I get the wort volume up to where I want it. It is easiest for me to use a smaller vessel to sparge into because I am mashing on the kitchen stove with a range hood in my way. Bigger pots, bigger pans, etc just do not fit.

 

[ChiknNutz]

In reference to the "BrewInaBag" video, he mentions a what seems like a high water volume/grain ratio...around 3 qts/lb. Is this typical of the BIAB method? If not, what is your method of strike water volume calculation?

 

[Oginme]

In reference to the "BrewInaBag" video, he mentions a what seems like a high water volume/grain ratio...around 3 qts/lb. Is this typical of the BIAB method? If not, what is your method of strike water volume calculation?

I am doing full volume BIAB. Adding in all my water in the mash and my mash thckness is usually around 7 to 7.5 l/kg (3.35 to 3.7 qts/lb).