Does squeezing or pressing eliminated need for sparging?

[hezagenius]

I’m looking to do my first BIAB and I have some questions. I tried all-grain once many years ago and it was an absolute disaster. The beer was horrible and the process was a PITA. I think the efficiency was in the 60's. After that, I went back to extract and have been doing those ever since. I’m looking to step it up a little by trying BIAB.

Just trying to get some ideas about what influences BIAB efficiency.

Would I get a better efficiency if I: a) did the BIAB with the full amount of strike water all at once, or b) used say 80% of the water for the initial mash and then sparged with the remaining 20%? My guess is the second option has higher efficiency but I’d like to hear if that is actually true or not.

If I squeezed/pressed the bag, would I get similar efficiency regardless of which method I used in the previous question?

 

[Rockn_M]

When I do BIAB I never sparge. I do full volume, plus increase the temp to about 165 after mashing and then squeezing the hell out of the bag. Because the grains are still very hot I put the grain bag in a colander, over a bucket and push down on the grains with a small lid until the sweet wort stops dripping out. Then I readjust the grains and push down again. I do this a few times until I stop getting drips. For BIAB I probably get around 75-80% efficiency.

Also to help increase your efficiency make sure you have a good crush on your grains. Either double crush your own grains or ask wherever you get your ingredients to double crush your grains for you.

 

[RM-MN]

The milling of the grain is the biggest factor in efficiency but you can pick up just a little more if you do a small sparge. I measured the difference at about 5% gain.

 

[hezagenius]

I've read that squeezing grain bags can extract unwanted tannins. Wouldn't that be an issue with squeezing/pressing BIAB bags?

 

[eadavis80]

I've done 3 BIAB. My first two had really, really bad efficiency and they had the full water in the mash/boil. My third one I had a thicker mash and dunk sparged and squeezed the bag after the mash and after the sparge. Not sure if sparging or squeezing (or both) were the reason, but my efficiency improved. My wort SAMPLE tasted fine on the one I squeezed the bag on. Have not drank that beer yet, but the wort sample tasted okay. Not sure when in the process you're supposed to be able to taste tannins.

 

[Rockn_M]

I've read that squeezing grain bags can extract unwanted tannins. Wouldn't that be an issue with squeezing/pressing BIAB bags?

I've heard that too but I think that is old school thinking. At least in my experience I haven't had an issue.

 

[hezagenius]

I've also seen some no-sparge discussions call for scaling up the amount of grain. Presumably this is to compensate for not capturing as high a % of the sugars in the grains by not sparging?

If you squeezed/pressed the grain bag, would that eliminate the need to scale up the grain bill?

 

[Rockn_M]

I've also seen some no-sparge discussions call for scaling up the amount of grain. Presumably this is to compensate for not capturing as high a % of the sugars in the grains by not sparging?

If you squeezed/pressed the grain bag, would that eliminate the need to scale up the grain bill?

It all depends on what your efficiency. If you have a low efficiency then you'll need to increase your grain bill. If you use brewing software I would put a guestimate for efficiency of 70% and then you adjust as needed.

 

[TexasWine]

Tannin extraction requires high pH and temps above ~170F. You will not extract tannins by pressing on your bag.

My vote would be to go full volume mash if you have the space in your kettle. I'm a sparger only out of necessity due to volume constraints.

 

[hezagenius]

I've got a 15 gal kettle so I should have enough room for a full volume mash.

 

[doug293cz]

Just trying to get some ideas about what influences BIAB efficiency.

Would I get a better efficiency if I: a) did the BIAB with the full amount of strike water all at once, or b) used say 80% of the water for the initial mash and then sparged with the remaining 20%? My guess is the second option has higher efficiency but I’d like to hear if that is actually true or not.

If I squeezed/pressed the bag, would I get similar efficiency regardless of which method I used in the previous question?

There are two types of efficiency you need to worry about:

Conversion Efficiency: This is the amount of starch converted to sugar in your mash divided by the theoretical maximum amount of sugar obtainable from the grain. The "theoretical" maximum is actually determined by a special type of laboratory mash.

Lauter Efficiency: The amount of sugar that ends up in your boil kettle divided by the total amount of sugar that you created by conversion in the mash.

The overall mash efficiency is the conversion efficiency times the lauter efficiency.

Most efficiency problems with BIAB turn out to be conversion efficiency problems. Conversion efficiency is a function of crush (grain particle size), time, temp, pH, and agitation. Finer crushes convert faster than coarser crushes due to diffusion effects. So, you can compensate for a coarse crush by doing a longer mash in order to get closer to 100% conversion. If conversion is incomplete, and you do a hot water sparge, you may get additional conversion due to the extended time and additional agitation (same with a mash out.) Agitation helps speed up conversion by short circuiting some of the diffusion limited processes. If you have poor conversion efficiency, you cannot completely fix it with a sparge.

Lauter efficiency depends on the volume and SG of the wort retained by the grain after draining. The gravity points retained equals the volume of retained wort times the SG-1 of the retained wort. Lauter efficiency equals BK points / (retained points + BK points).
Both squeezing and sparging reduce the retained points. Squeezing by reducing the amount of retained wort. And sparging by reducing the SG of the retained wort. A thinner mash starts out with lower SG for the retained wort.

So, the answer to whether sparging or squeezing creates the higher efficiency is that you get the maximum efficiency by doing both. If you only do one or the other, it depends. A very aggressive squeeze will produce better efficiency than a low volume and/or poorly conducted sparge. A good sparge will give higher efficiency than a weak squeeze. And, a very extended gravity drain may produce an efficiency equal to a squeeze.

Which is better depends on the exact process. Some people would rather squeeze than sparge, others don't like squeezing, and either sparge and/or use an extended drain. Any and all combinations will work. It's a matter of personal preference. As long as your getting an efficiency acceptable to you, you don't need to change anything.

If you are unhappy with your efficiency, then you first need to determine whether your conversion efficiency or lauter efficiency, or both, are causing the problem. With BIAB you should be able to achieve 95% or better conversion efficiency, and 80% or better lauter efficiency. For help on diagnosing efficiency problems, check out my posts here, here, and here.

Brew on

 

[Murphys_Law]

I just did a BIAB and was unhappy with the efficiency so was thinking of changing things up a bit. I'm going to hold about 2G of water back and do an hour mash with full volume minus this 2G. When complete I'm going to drain this into my smaller kettle and then pour the remaining 2G of water, heated to 170, over the grain and let it drain into my smaller kettle. I will have no water above the false bottom in my large kettle so instead of lifting the heavy, wet grain bag out and let it drain or squeeze it or whatever, I was going to use a potato smasher and "squeeze" the bag while it's sitting on the false bottom (all the water will drain into my smaller kettle, too).

Once this is done I'll remove the grain bag (and false bottom) and pour the wert back into the large kettle for boiling.

Does this make sense? Not sure I need to sparge with 170 degree water...thoughts on this step? This just seems to me as a mix between sparge and squeeze and really doesn't add too many extra steps to my brew day.

 

[balrog]

Some sparge with room temp water. Some contend the pour-over doesn't rinse well as it run around the grain mass not through. Some therefore swear by the dunk sparge. Unfortunately, you find what works well for you only by finding what works well for you. I vote 1 for mash regular volume (1.5 qt/lb) dunk sparge in 1-2 gal. But I am limited by 5G pot and do partial boil. YMMV.

 

[jaydlaw]

I only performed 1 Biab so i don't know too much. on my next attempt I will Squeeze the bag more. I attempted to my first time but I wasn't very successful. i need to find a technique with my set up which will allow for me to squeeze more out of the bag. One thing that i did, was mash for 90 minutes instead of 60. Originally i was going to mash for 60 but as i got into it, i felt that a 90 mash would be more beneficial. My efficiency wasn't great (i believe it was around 67%) but all of the samples i taken (wort, quick gravity checks, bottling) where very tasty. i won't sparge, that's not something that i want to do. i feel i can get better efficiency by squeezing more and possibly double crushing/ fine crushing my grains. I eventually need to invest in my own grain crusher.

 

[Homercidal]

You can do a full mash and not sparge. You can do a sparge and reserve some of the water for the sparge. You can squeeze or not squeeze in either case.

A no-sparge mash will not be as efficient as a sparge. Most people who do this prefer the ease of brewing and perceived quality over the relatively small additional cost of the added grains needed to make up for the loss in efficiency.

When I BIAB I have plenty of kettles, but nothing big enough to do a full mash. And I am use to batch sparging, so I save some water from the mash and use it to sparge with by dunking the bag in a separate kettle and then combining the worts. I don't squeeze, but that's just because I never wanted to mess with setting it up. I have a device that holds the grain bag over the kettle and I just let it drop while the boil heats up. No doubt there could be less loss if I squeezed, and I don't believe it will hurt the flavor of the beer, but at this point I just don't have the interest.

BIAB can be fairly efficient depending on the process you use. I think, though, that efficiency is overrated. Most people are looking to save time and use a simplified process without having to pay for fancier equipment.

BIAB really is a nice way to get into AG without spending much money.

 

[dkevinb]

My first BIAB was full-volume, no-sparge, standard mill, and I got 65% kettle efficiency.The next batch was exactly the same except I double-milled the grain and got 77% kettle efficiency. Then I started doing larger batches which required me to dunk sparge/mash out in 170 degree water in a second kettle, and I got 77 - 78% kettle efficiency. I just bought a larger kettle and did a full-volume, no-sparge, no mash out batch last weekend and got 77% kettle efficiency.

So in my experience double-milling the grain has the biggest impact on efficiency. The only reason I'd sparge/mash out is if I was trying to do a batch larger than my main kettle could hold.

As a side note, I prefer to use kettle efficiency instead of brewhouse efficiency because it's a better indicator of how much sugar you're extracting. Brewhouse efficiency will go up or down drastically depending on how much trub you transfer to the fermenter. I'm not shooting for maximum efficiency. I just want "decent" efficiency that's consistent so I can plan my recipes.

 

[McKnuckle]

I never sparge with BIAB, neither dunk nor pour-over. I gravity drain the bag over a period of about 30 minutes, and I sometimes squeeze a bit at the end. I crush at the default/fixed setting on my Schmidling MaltMill, running the grain through once.

My lowest mash efficiency has been 74%, and my highest 84%.

There is a thread like this nearly every few days, and for the life of me I don't understand the "efficiency epidemic" that people seem to experience with BIAB. It just works if you follow a few basic guidelines. There are no tannins. Cloudy wort doesn't mean cloudy beer. Efficiency is on par with other methods. Etc. Etc. The same things keep coming up and the answers are the same.

One thing that isn't always mentioned is to limit the volume of water that is floating around outside the bag. Try to get the bag to fill the mash tun like a second skin, so that all the grain and water are contained within the confines of the bag. That seems to make a difference.

 

[dkevinb]

I never sparge with BIAB, neither dunk nor pour-over. I gravity drain the bag over a period of about 30 minutes, and I sometimes squeeze a bit at the end. I crush at the default/fixed setting on my Schmidling MaltMill, running the grain through once.

My lowest mash efficiency has been 74%, and my highest 84%.

There is a thread like this nearly every few days, and for the life of me I don't understand the "efficiency epidemic" that people seem to experience with BIAB. It just works if you follow a few basic guidelines. There are no tannins. Cloudy wort doesn't mean cloudy beer. Efficiency is on par with other methods. Etc. Etc. The same things keep coming up and the answers are the same.

One thing that isn't always mentioned is to limit the volume of water that is floating around outside the bag. Try to get the bag to fill the mash tun like a second skin, so that all the grain and water are contained within the confines of the bag. That seems to make a difference.

Good point on the efficiency. This isn't a contest to see who can extract the most sugar. OTOH, BIAB is better at it than non-BIABers will acknowledge. My LHBS guy told me I'd never hit 65% and I routinely exceed 80% without trying too hard. In any case, if I can consistently hit the mid- to high-70's I'm happy. That means I can plan my recipes and consistently hit my OG. If I have to add an extra half-pound of 2-row, so be it.

 

[balrog]

One thing that isn't always mentioned is to limit the volume of water that is floating around outside the bag. Try to get the bag to fill the mash tun like a second skin, so that all the grain and water are contained within the confines of the bag. That seems to make a difference.

Testify.

 

[hezagenius]

For those that don't sparge, do you scale up the grain bill to make up for lost sugar extraction from the sparge?

 

[Oginme]

For those that don't sparge, do you scale up the grain bill to make up for lost sugar extraction from the sparge?

When I BIAB, I use the full amount of water (Mash + Sparge) that someone would use in a standard 3 vessel system. My mash efficiency is around 85% to 86% versus when I use my cooler and do a more traditional mash, my efficiency is in the upper 70's. I actually cut back on grain when I scale to the BIAB mashes.

 

[McKnuckle]

For those that don't sparge, do you scale up the grain bill to make up for lost sugar extraction from the sparge?

No. Because there is no lost sugar extraction.

There's a misunderstanding about full volume BIAB: It involves a passive sparge.

Sparging is done because you mash with part of the water needed for boiling, and rinse with the rest of the water. In full volume BIAB, you mash with ALL of the water. So there is no need for a separate sparge step. You have all the water already, and all of the sugar dissolves into it.

I calculate my recipes based on efficiency, absorption, evaporation, and other losses just like any other method. There is no need to compensate for something inherently missing in the BIAB approach.

 

[Homercidal]

No. Because there is no lost sugar extraction.

There's a misunderstanding about full volume BIAB: It involves a passive sparge.

Sparging is done because you mash with part of the water needed for boiling, and rinse with the rest of the water. In full volume BIAB, you mash with ALL of the water. So there is no need for a separate sparge step. You have all the water already, and all of the sugar dissolves into it.

I calculate my recipes based on efficiency, absorption, evaporation, and other losses just like any other method. There is no need to compensate for something inherently missing in the BIAB approach.

This isn't quite true. The efficiency is lower because the mash water container a higher percentage of sugars and some of that water remains in and on the grain when you drain/strain it.

When you sparge you recover some of, or most of, the sugars from the spent grain. That's it's purpose.

So even though you do a full mash some of the sugars that are converted are still on, and in, the spent grain and you don't rinse it out.

Therefore more grain is needed to make up the difference.

 

[McKnuckle]

Therefore more grain is needed to make up the difference.

Empiricism is King, and I've personally not seen that to be true.

The amount of water absorbed by grain is about 0.10-12 gal/lb for traditional mashing where you remove water from the grain, but the grain mass stays intact inside the mash tun.

The amount of water absorbed by grain is about 0.05-0.08 gal/lb for BIAB where you remove the grain from the water. That's much less water remaining with the grain.

Also, efficiency calculations in brewing software don't care what method you use. They are simply math, and are either met or missed in practice. If you get 80%, you get 80%. And I do - as do others.

In any event, I'm 100% convinced that BIAB is an absolute equal to traditional 3 vessel brewing in every way that matters to a home brewer. Both methods have things to watch out for and best practices to follow. If you do either one right, you're making quality beer with a valid all grain process.

 

[ZebulonBrewer]

This isn't quite true. The efficiency is lower because the mash water container a higher percentage of sugars and some of that water remains in and on the grain when you drain/strain it.

When you sparge you recover some of, or most of, the sugars from the spent grain. That's it's purpose.

So even though you do a full mash some of the sugars that are converted are still on, and in, the spent grain and you don't rinse it out.

Therefore more grain is needed to make up the difference.

Sugar will be left behind, yes, but not more than is left behind by a perseon with a two-three vessel setup who gets the same efficiency.

If your three-vessel plus 60 minute fly sparge gets you 92% efficiency vs. 80-85 with BIAB, then yes, you have sugar 'left on the table', so to speak, but most people don't get 90%+ efficiency. Most of us get much less.

 

[Homercidal]

Sugar will be left behind, yes, but not more than is left behind by a perseon with a two-three vessel setup who gets the same efficiency.

If your three-vessel plus 60 minute fly sparge gets you 92% efficiency vs. 80-85 with BIAB, then yes, you have sugar 'left on the table', so to speak, but most people don't get 90%+ efficiency. Most of us get much less.

I'm not talking about a 2 or 3 vessel system. I'm simply stating that a rinse will get those sugars that were left on the grain into the boil kettle. So your efficiency should go up. How much depends on your sparge method and strain/drain.

I have nothing against BIAB. Never claimed to. I do use it sometimes for smaller batches when the grain bill makes my cooler mash tun lose more heat than I like.

 

[McKnuckle]

I guess it's a red herring, though, because there will always be something left in/on the grain with any method. Otherwise we'd all get 100% extraction and not have these discussions constantly.

 

[Homercidal]

I guess it's a red herring, though, because there will always be something left in/on the grain with any method. Otherwise we'd all get 100% extraction and not have these discussions constantly.

This is true and why efficiency is measured against what a lab could extract with an ultra-fine crush and everything just right. That's what they deem to be 100%. And even that is not truly 100%, just the new base line for brewers to measure their efficiency against.

My only point is that regardless of equipment, a no-sparge process will leave behind a certain amount of sugars compared to a sparge method.

Some people strive for higher efficiency assuming that it's like building a faster race car, and some people eschew efficiency believing a no-sparge method makes a better tasting beer.

Anecdotally, I have read a few things that seem to indicate that while there are several things responsible for efficiency gains, only grain crush makes a real big difference when using any of the common brewing methods. All others contribute relatively small changes. And I'm talking about mash efficiency, not brewhouse efficiency.

 

[grainbill]

I've read that squeezing grain bags can extract unwanted tannins. Wouldn't that be an issue with squeezing/pressing BIAB bags?

same goes for extended sparge times, or so I've heard...

 

[ArcLight]

Q: My Biab efficiency is low, should I xxxxxxx .....

A:
1. Crush tighter
2. Crush tighter
3. Crush tighter
4. Perform a dunk sparge with 35% of the water.
5. Did you remember to crush tightly?
6. See #1

 

[doug293cz]

Sugar will be left behind, yes, but not more than is left behind by a perseon with a two-three vessel setup who gets the same efficiency.

This is almost a tautology. Since efficiency, by definition, is a measure of sugar not left behind. The percentage of sugar left behind is 100% - mash efficiency.

Brew on

 

[balrog]

This is almost a tautology. Since efficiency, by definition, is a measure of sugar not left behind. The percentage of sugar left behind is 100% - mash efficiency.

Brew on

Great. I *HATE* it when I have to look up words like "tautology" when reading these forums.

 

[doug293cz]

I've read that squeezing grain bags can extract unwanted tannins. Wouldn't that be an issue with squeezing/pressing BIAB bags?

same goes for extended sparge times, or so I've heard...

Tannins get extracted only if the pH gets too high (above about 6), and the temperature is over about 170°F. Keep your pH in the correct range (by controlling your water chemistry vs. grain bill), and you will not extract tannins. You can't press hard enough during a squeeze to mechanically extract tannins. Alaskan Brewing actually uses an industrial scale filter press to extract wort from the mash. This represents the ultimate in squeezing capability.

If you use hot sparge water with too high alkalinity, then the sparge can extract tannins, because the pH goes up when using high alkalinity sparge water, since the grain's pH buffering capability is greatly reduced after initial run off. Fly spargers have to be particularly careful about this, as towards the end of the sparge the grains have essentially no pH buffering capability left.

Brew on

 

[doug293cz]

Great. I *HATE* it when I have to look up words like "tautology" when reading these forums.

Your vocabulary word for the day: Tautology

You're welcome, and brew on

 

[balrog]

Alaskan Brewing actually uses an industrial scale filter press to extract wort from the mash. This represents the ultimate in squeezing capability.

I was just reading about that. Man, I wish I could get some Alaskan Amber shipped to MA without having to sell the wife and kids to pay shipping.

 

[balrog]

dbl post hell

 

[wardens355]

This isn't quite true. The efficiency is lower because the mash water container a higher percentage of sugars and some of that water remains in and on the grain when you drain/strain it.

When you sparge you recover some of, or most of, the sugars from the spent grain. That's it's purpose.

So even though you do a full mash some of the sugars that are converted are still on, and in, the spent grain and you don't rinse it out.

Therefore more grain is needed to make up the difference.

I used to mash -> drain -> sparge -> drain, now I mash -> mashout full volume -> drain. I used to get around 80% brewhouse efficiency, now I get around 70% brewhouse efficiency and adjust up the grain accordingly. It's like rinsing with one large volume vs a bunch of small volumes equal to that large volume. You will remove more of the contaminant (sugar in this case), if you rinse in a bunch of smaller volumes, but rinsing more is a PITA and homebrewing gains between 70% to 80% efficiency is small potatoes, so I stopped.

 

[Homercidal]

I used to mash -> drain -> sparge -> drain, now I mash -> mashout full volume -> drain. I used to get around 80% brewhouse efficiency, now I get around 70% brewhouse efficiency and adjust up the grain accordingly. It's like rinsing with one large volume vs a bunch of small volumes equal to that large volume. You will remove more of the contaminant (sugar in this case), if you rinse in a bunch of smaller volumes, but rinsing more is a PITA and homebrewing gains between 70% to 80% efficiency is small potatoes, so I stopped.

I haven't settled on any one method. I still go between 1-2 sparges depending on the strength of the beer and what equipment I'm using at the time.

I could see me doing a full volume sparge if it will fit my mash tun.

I do have plans to build a hydraulic fruit press before the summer ends (again this summer...) and I could use that to squeeze the bag. I'm not sure it's worth it, though.

How much more do you get from squeezing versus just letting it drain?

 

[wardens355]

I haven't settled on any one method. I still go between 1-2 sparges depending on the strength of the beer and what equipment I'm using at the time.

I could see me doing a full volume sparge if it will fit my mash tun.

I do have plans to build a hydraulic fruit press before the summer ends (again this summer...) and I could use that to squeeze the bag. I'm not sure it's worth it, though.

How much more do you get from squeezing versus just letting it drain?

I don't do BIAB, so don't know. I would guess that you would get some small increase in efficiency if you squeeze, maybe more so if you squeeze on the first runnings than the sparge runnings (since the absorbed water is higher strength during first running). More volume and more overall sugar. Boil for a few mins longer, higher final gravity. You should be able to determine the boost in efficiency if you can estimate the maximum amount of water you can squeeze out per lb of grain used.

 

[Gavin C]

This type of thread crops up all the time because of the oft touted disadvantages of BIAB which are demonstrably not the case.

Low efficiency being front and center.

Solution crush fine.

Sparge or no sparge debate is really of secondary importance

With full-volume no-sparge brewing with a fine crush conversion efficiency will be 90+ % and you will lose sugars to absorption. That amount will depend on the volume of sweet-wort retained by the grain. This sweet-wort will have the same gravity as that in the boil kettle/ mash-tun.

Typically this is about 0.045 gallons per pound of grain in my simple squeezer's setup.

0.4 gallons lost to absorption in 9lb of grain

If you are not doing full volume mashing then the absorbed wort is higher gravity. More sugars are in the grain. A sparge to the desired pre-boil volume will extract some more of these sugars. It's a little extra work but you will get more sugars out from that higher gravity sweet-wort retained by the grains.

The question of benefit of a sparge relates to the extra sugars extracted by the process versus the extra sugars that would not have been lost in the first place if a thinner full-volume mash had been used. A thinner mash means a lower gravity sweet-wort retained by the grains, less sugars retained.

Depending on the planned OG and associated grain-bill a sparge or no-sparge may be of more benefit.

In my setup, with 5.5 gallons batches, full-volume no-sparging equates to me formulating my recipes at 80% brewhouse efficiency and hitting my numbers. (i.e.: Brewing the beer that was intended in the volume I intended).

I am willing to accept a lower BH eff. figure with bigger beers and will adjust the grain-bill accordingly. This is a moot point however as I brew beers with OG under 1.060

PS: Mill fine. (Coarse corn meal is what my grain looks like with a single pass at my mills narrowest setting) The rest is all tweaking the process. Therein lies the fun and debate.