What BIAB brewing actually is (Mythbusting for traditionalists)

[Bobby_M]

That makes sense. Removing sparging step still allows for enough sugars to be converted from the grain for a nice beer? I seen some say squeeze out bag and others say don’t. I think it has to do with tannins or something. What is your opinion?

The sugars are made in the mash whether you sparge or not. When you pull the bag of spent grain out, some of that sugary wort "clings" to the ball of grain and gets lost. Sparging simply gets SOME of that back for you. In my opinion the extra extraction is not worth the extra water handling, volume calculations, etc because as some of the posts above speculate, it's the difference of about $2-3 in extra grain cost.

Tannin extraction is related to mash pH but save that can of worms for another day. A gentle squeeze of the bag is all you need. If you find you're not getting the volume of wort out that you need, start with more water next time.

 

[Bobby_M]

I squeeze mine like it owes me money. Every ounce counts.........

The experimentation I did recently contrasting mash fines in the boil against clean wort in the boil seems to suggest it would be better to let it gravity drain and spend the extra dollar in lost efficiency.

 

[RM-MN]

That makes sense. Removing sparging step still allows for enough sugars to be converted from the grain for a nice beer? I seen some say squeeze out bag and others say don’t. I think it has to do with tannins or something. What is your opinion?

A sparge can increase the brewhouse efficiency by 5-10% so it isn't really necessary. I do it because the pot that I mash in is a little small to get the entire amount of liquid plus the grains to reach my desired volume of wort. Adding a tiny amount of grain to the mash can make up for the lack of a sparge. Milling your grains finer can have more effect than adding grain to the mash.

Squeeze the bag all you want. If you ever get to where you can squeeze out the tannins, I have a job for you to take the place of a rock crusher.

Tannin extraction requires a pH of over 6.0 coupled with a temperature of over 170F. I sparge with cold water so I never reach the 170F threshold. That way I don't need to worry about the pH.

Most people do not know how long it really takes for the conversion of starches to sugars so they just use the rule of thumb and mash for an hour. Most conversion happens fast so don't get too worried about adding heat to the mash. If you decide you really need to, you have to stir continuously and vigorously to keep from destroying the enzymes that are responsible for the conversion.

 

[doug293cz]

Removing sparging step still allows for enough sugars to be converted from the grain for a nice beer?

As Bobby said, whether you sparge or not does not affect the amount of sugar created by the mash process. If your grain absorption was a total of 1 gal for a given batch, if you don't sparge you might be leaving 1 gal of 1.045 wort trapped in the grain, whereas if you batch sparged, you would also be leaving 1 gal, but only at an SG of 1.022. The sugar you didn't leave in the grain ends up in your boil kettle. Your lauter efficiency might go from 79% up to 90%, but that only saves you about 1.3 -1.4 lb of grain on a 5 gal batch.

Brew on

 

[DadRocks73]

Thanks for all the great advice. I suppose “keep is simple stupid” really applies here. I guess I just need to go grab some ingredients and a bag and do this.

 

[Willy]

I do a hybrid of this. I mash ... Using an almost full volume and do a short pass of fly sparging. Just "first running" ... After that, seems like a lot of effort with little return. (About full volume minus 1/2 gal to 1 gal, followed by a 1/2 gal to 1 gal sparge water. Basically, just topping off to get to full boil volume (which goes for an hour, about .79 gal reduction.) I end up with my "batch volume" - usually about 5.75 gallons which ends up as a 5 gallon to serve.

But I totally get the no sparge, full volume mash. You end up saving like ? 75¢? 1.15? I don't know. It ain't much with our small volumes.

 

[AlexKay]

Thanks for all the great advice. I suppose “keep is simple stupid” really applies here. I guess I just need to go grab some ingredients and a bag and do this.

Single-temperature mash in the bag, pull and gently squeeze or gravity drain when the mash is done. No mash out. As you say, keep it simple, and take measurements and notes to help you repeat and/or refine in future batches.

Once everything becomes well controlled and predictable and you’re making great beer, you can worry about complicating things.

 

[AdjunctBrewer]

Thanks for all the great advice. I suppose “keep is simple stupid” really applies here. I guess I just need to go grab some ingredients and a bag and do this.

At it's simplest a strike water calculator will come in handy for brew day. There's many of them online but most use the equations in John Palmers book 'How To Brew':

https://homebrewacademy.com/strike-water-temp-calculator/

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If you're interested in further reading:

Circa 1998 Ken Schwartz wrote a paper concerning No-Sparge and Batch sparge, and the math involved.

https://www.bayareamashers.org/wp-content/uploads/2013/07/nbsparge.pdf

Denny Conn further promoted the batch sparge concept using coolers:

http://www.dennybrew.com/

https://www.doc-developpement-durab...ets-Outils-Produits/bieres/CoolerSparging.pdf

Voile bags, nylon paint strainers, etc... were introduced and placed in the coolers or pots, eliminating the need to modify them with false bottoms and mash strainers, etc... All in one systems (EBIAB) started to appear with heating elements and recirculating pumps for step mashing and maintaining temperature. False bottoms were again used to offset the bag off the bottom of the pot to make room for the heating elements and pump outlets and returns.

Software such as Brewers Friend or BeerSmith have calculators that will help assess the quantity of grains, water volumes and temperatures required.

There are also many free online calculators (search for strike water calculator, batch sparge calculator, no sparge calculator, biab calculator, infusion mash calculator, step mash calculator):

https://simplebiabcalculator.com/

 

[Closet Fermenter]

This a type of fly sparging that is less efficient and more prone to channeling than traditional fly sparging (I'd recommend avoiding this process as it's very prone to over extraction).

Hey, Bobby. Your comment above is about the “pour over “ sparge. Can you explain a little bit more about what you mean by over extraction? I thought my goal was to get as much of the sugars out as possible. Is this not true, or are there other things being extracted by this method that I don’t want? I may be misunderstanding you and you just mean “over extraction” in terms of volume of wort. Always appreciate your input.

 

[Closet Fermenter]

Squeezing the bag does not cause tannin extraction. Many commercial breweries use industrial filter presses to squeeze much harder than you ever could. They wouldn't use this process if it extracted tannins.

Now that’s interesting; something I never knew. Of course, I have practically zero knowledge of commercial brewing, so it’s not difficult to surprise me.
When I read this my thoughts went immediately to my fruit press that I use for making wine. Why couldn’t I drop my sack of grains over into the press and put the squeeze on them in a serious way? I could probably set it up with the spout on the press draining right into the boil kettle.
Has anyone tried this, or can you think of a reason that I should not do this?

 

[DBhomebrew]

The tannin problem with "over sparging" isn't the removal of too much sugar which thereby uncovers an underbelly of tannins. The problem is rinsing away enough pH buffering compounds to the point where the remaining water/wort mix shifts out of the ideal pH range. Use RO, distilled, or carefully salt-adjusted water and you can sparge until the cows come home.

However, you'll likely reach a point of diminished returns long before then. For me, that's a well executed single dunk sparge for a not inconsequential 8% bump in lauter efficiency over a full volume mash.

Most importantly it's a highly predictable run-off and lauter efficiency, same as what Bobby touts for the full volume. I've just got an extra step and another vessel to clean. Just a simple bucket and since it's just diluted wort, not any cooked on proteins etc, it's the easiest clean of the brew day.

Don't worry about maximizing mash efficiency. Maximize conversion efficiency, 100%. As far as lauter efficiency goes, maximize predictability via repeatable process. Want to squeeze? Sure. But squeeze to a consistent loss-to-grain absorption ratio. Want to sparge? Sure. Squeeze (or not) each running to the same loss-to-grain. Open the bag in the dunk water, mix it to a homogeneous slurry. (This is where a dunk sparge performs better than a fly with regard to BIAB. Yes, a well executed fly is more efficient than a single or double dunk, but it's nearly impossible to execute a fly with a solid mass of grain ball.)

Once you settle in on a process, and can perform it repeatedly, you can easily send into the kettle whatever wort of whatever composition, volume, and gravity you choose.

 

[AdjunctBrewer]

Hey, Bobby. Your comment above is about the “pour over “ sparge. Can you explain a little bit more about what you mean by over extraction? I thought my goal was to get as much of the sugars out as possible. Is this not true, or are there other things being extracted by this method that I don’t want? I may be misunderstanding you and you just mean “over extraction” in terms of volume of wort. Always appreciate your input.

Extract brewers (at least some of them) would most likely sparge their steeping grains by pouring a small amount of liquor over them, though most extract kit instructions don't specify this.

BIAB brewers will sometimes place their bag in a colander or on a grate above the boil pot, open the bag and pour (acidified) liquor over their grains (maybe dispersing it with a perforated spoon so as not to cause channeling).

Now that’s interesting; something I never knew. Of course, I have practically zero knowledge of commercial brewing, so it’s not difficult to surprise me.
When I read this my thoughts went immediately to my fruit press that I use for making wine. Why couldn’t I drop my sack of grains over into the press and put the squeeze on them in a serious way? I could probably set it up with the spout on the press draining right into the boil kettle.
Has anyone tried this, or can you think of a reason that I should not do this?

What do you believe you'll gain by doing this? More extract? More volume? Are you adjusting your mash pH and temperature such that you won't extract tannins? Can you accomplish the same goal with more grain?

If you have a good reason for doing it and understand the in's and out's of what you're doing, why wouldn't you? If you're just doing it because you can or you think squeezing grain bags with wine presses is cool, then you might want to reconsider your process.

 

[DBhomebrew]

Squeezing the bag in a press does not risk tannin extraction. No need to worry about mash or sparge water pH or buffering ability. No need to worry about mash temp. You're not changing the composition of the grain ball, you're just squeezing it for all the wort it's worth.

Rinsing (sparging) does risk tannin extraction as you are changing the composition and buffering ability of the wort.

 

[AdjunctBrewer]

Squeezing the bag in a press does not risk tannin extraction. No need to worry about mash or sparge water pH or buffering ability. No need to worry about mash temp. You're not changing the composition of the grain ball, you're just squeezing it for all the wort it's worth.

An appropriate pH and temp is always necessary otherwise you risk extracting tannins not only in the mash but also in the press (not because of the press pressure but because you're pressing out more of the high pH extract). A mash with a high pH and temp will extract tannins either way.

Rinsing (sparging) does risk tannin extraction as you are changing the composition and buffering ability of the wort.

True but can be easily compensated for with sparge liquor acidifcation and/or monitoring of extract SG.

 

[mac_1103]

Are you adjusting your mash pH and temperature such that you won't extract tannins?

If he isn't doing this then squeezing the bag (or not) isn't going to be the issue.

Sparge at ambient temperature and acidify the sparge water. Zero risk of extracting tannins. Unless you already extracted them in the mash.

 

[DBhomebrew]

Right.

An appropriate pH and temp is always necessary otherwise you risk extracting tannins not only in the mash but also in the press (not because of the press pressure but because you're pressing out more of the high pH extract). A mash with a high pH and temp will extract tannins either way.

Of course. Mash pH and temp is massively important and should absolutely be understood and controlled. Whether or not one does a simple gravity drain or a bone-dry pressing.

True but can be easily compensated for with sparge liquor acidifcation

Of course. Mentioned in my post above. My point being that squeezing does not bring any new risk of tannin extraction. Introduction of new water does. Be aware, control as needed, brew on.

monitoring of extract SG.

Monitoring SG to control pH is like monitoring skin color to check internal temp of a turkey.

 

[Willy]

Never had an issue with squeezing the bag and getting an off flavor... Until this crazy white haired dude shows up in a DeLorian and deposits a guy named Biff in my mash pipe. Thankfully, he took me back in time and that took care of the Tannen problem .

 

[AdjunctBrewer]

Monitoring SG to control pH is like monitoring skin color to check internal temp of a turkey.

Sparge extract SG is monitored as an indicator of pH rise as extract falls (inverse relationship) not as a method of controlling pH.

Sparge liquor acidification is generally the means of controlling pH but on the homebrew level there's generally such small volumes necessary to reach boil volume, it (monitoring of sparge extract SG) most likely isn't as productive (or even necessary) as it would be in a several hour commercial sparge.

Though if one has a refractometer it wouldn't take very much effort or time and might be worth recording "remaining extract" as an additional indicator of process efficiency.

 

[DBhomebrew]

Sparge extract SG is monitored as an indicator of pH rise as extract falls (inverse relationship) not as a method of controlling pH.

Of course monitoring doesn't control, I wouldn't expect it to. Monitoring gives you information as whether you should/need to control. Just as watching skin color (monitoring SG) doesn't tell you when to pull the turkey from the oven, knowing the internal temp (pH) does. There's a possible correlation in some situations, but not all. Therefore no rule.

For example, run off SG has no relationship to pH of the wort remaining in the the grain ball when one uses RO or distilled water to sparge. The sparge water in this case has zero buffering, no pH shift.

 

[AdjunctBrewer]

Of course monitoring doesn't control, I wouldn't expect it to. Monitoring gives you information as whether you should/need to control. Just as watching skin color (monitoring SG) doesn't tell you when to pull the turkey from the oven, knowing the internal temp (pH) does. There's a possible correlation in some situations, but not all. Therefore no rule.

For example, run off SG has no relationship to pH of the wort remaining in the the grain ball when one uses RO or distilled water to sparge. The sparge water in this case has zero buffering, no pH shift.

I think we're saying the same thing.

 

[DBhomebrew]

I think we're saying the same thing.

Excluding the thing about mash pH and temp being a concern raised by using a wine press for lautering or the other thing about run-off SG being, as a rule, an accurate gauge of grain bed pH, sure.

 

[AdjunctBrewer]

Not sure how you got this:

Excluding the thing about mash pH and temp being a concern raised by using a wine press for lautering

From this:

An appropriate pH and temp is always necessary otherwise you risk extracting tannins not only in the mash but also in the press (not because of the press pressure but because you're pressing out more of the high pH extract). A mash with a high pH and temp will extract tannins either way.

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Not sure how you got this:

the other thing about run-off SG being, as a rule, an accurate gauge of grain bed pH, sure.

From this:

True but can be easily compensated for with sparge liquor acidifcation and/or monitoring of extract SG.

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[Closet Fermenter]

Did I just throw gasoline on fire?

 

[Yesfan]

The experimentation I did recently contrasting mash fines in the boil against clean wort in the boil seems to suggest it would be better to let it gravity drain and spend the extra dollar in lost efficiency.

Funny you mention that. I had to run a few errands today, during brew day, so I decided to do those after mashout. I let the bag drain into a second kettle while I was gone and figured I'd start the boil when I got back. I was surprised at the amount of wort I got vs squeezing the bag in the past. I squeezed it anyways to see how much more I'd get. Not that much. Probably just a few more ounces if anything.

Going forward, I'll probably just let it drain and add back if I need to. If anything, I could do a pour sparge into a second kettle and use those runnings in a yeaster starter for the next batch.

 

[InspectorJon]

I squeeze mine like it owes me money. Every ounce counts.........

I squeeze mine like it owes me beer…

 

[Bobby_M]

I squeeze mine like it owes me beer…

What I was suggesting is that it's possible it owes you a slightly lesser quality beer than it already gave you.

 

[Bobby_M]

Hey, Bobby. Your comment above is about the “pour over “ sparge. Can you explain a little bit more about what you mean by over extraction? I thought my goal was to get as much of the sugars out as possible. Is this not true, or are there other things being extracted by this method that I don’t want? I may be misunderstanding you and you just mean “over extraction” in terms of volume of wort. Always appreciate your input.

The key word is "channeling". If you had a ball of damp grain that occupied say a 5 gallon bucket and PERFECTLY rinsed it, it would look something like passing a 1" thick disc of water that had the same diameter as the bucket, from the top of the bucket straight down through the grain and out the bottom. Every particle of grain get the exact same amount of sugar rinsed off, no more no less.

The opposite of perfect would be that same volume of water arranged in the shape of a javelin pierced down through the center of the grain ball, stripping every molecule of sugar and who knows what else from just the core and leaving everything else untouched.

Maybe another way to think of it is taking just one scoop of grain out and rinsing that same amount 5 separate times. The end result is the same. Some of the grain is rinsed too much and other grain isn't rinsed at all. That's channeling and some level of that happens when you pour a sparge over.

The thing is, many people that do pour over sparging think they're doing a "pretty good" version of a fly sparge but they are functionally different.

 

[Bobby_M]

Squeezing the bag in a press does not risk tannin extraction. No need to worry about mash or sparge water pH or buffering ability. No need to worry about mash temp. You're not changing the composition of the grain ball, you're just squeezing it for all the wort it's worth.

Rinsing (sparging) does risk tannin extraction as you are changing the composition and buffering ability of the wort.

I mostly agree with this. I'd say if you've already landed your mash pH in the 5-5.6 range where husk material isn't likely to break down, squeezing hard isn't going to have any negative effect. However, if you've already performed your mash at a pH of 6.2 and the husk is softened, wouldn't tannin extraction be somewhat corollary to how hard you'd squeeze?

I know it would be fixing the wrong problem here. I'm thinking that plenty of brewers are currently unaware or unwilling to care for their mash pH so a hard squeeze would just objectively be worse for the beer.

 

[Bobby_M]

Funny you mention that. I had to run a few errands today, during brew day, so I decided to do those after mashout. I let the bag drain into a second kettle while I was gone and figured I'd start the boil when I got back. I was surprised at the amount of wort I got vs squeezing the bag in the past. I squeezed it anyways to see how much more I'd get. Not that much. Probably just a few more ounces if anything.

Going forward, I'll probably just let it drain and add back if I need to. If anything, I could do a pour sparge into a second kettle and use those runnings in a yeaster starter for the next batch.

This is why I leave my bag hanging over the kettle pretty much all the way to the first hop addition or at least until I don't see any drips for a while. By the time I drop that bag into the bucket headed for the compost pile, I only find another maybe 5 ounces of wort in the bucket.

I'm sure there is some variation based on the stickiness of the grain bill and mesh size of the bag. I'm using about a .025" mill gap and the Wilser bags (that get PBW soaked after every batch).

 

[Bobby_M]

If he isn't doing this then squeezing the bag (or not) isn't going to be the issue.

Sparge at ambient temperature and acidify the sparge water. Zero risk of extracting tannins. Unless you already extracted them in the mash.

I think it's somewhat intuitive but with one intermediate possibility

A high pH mash would perhaps make tannins more accessible to all future actions, any of which would be:

Pressing
Centrifuging
Sparging with acidified water
Sparging with any water

Whereas if you did none of those and just let the wort free run away from the grain, it would probably have less tannins even if the mash pH was high. That's my hypothesis and perhaps nonsense.