What BIAB brewing actually is (Mythbusting for traditionalists)

[DBhomebrew]

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.

True enough.

By trade and hobby I'm a troubleshooter. Before I got into brewing, I brought a classic bike back onto the road as my 365 day/yr commuter vehicle. I did so by educating myself the same way I did for brewing: an excellent online forum. A common issue on the forum was a symptom of a lean mix, popping on decel. Quite often the forum "wisdom" was to bump up the orifice size on the jets. Sure, the popping on decel often went away, but then there'd be all sorts of difficulty in balancing cylinders, low MPG, etc, etc. When the experts had a chance to cut through the forum noise and walk the new member through finding and fixing the various air leaks, all of a sudden the factory manual jet sizes worked. Both cylinders used the same size. They were easy to balance. Vibration would be cut in half. MPG dropped. The bike could be tuned.

Tannin extraction isn't a lautering problem, it's a pH problem. Best to approach it as such.

 

[Bobby_M]

Tannin extraction isn't a lautering problem, it's a pH problem. Best to approach it as such.

I think with everything, knowing you have a problem is the first step.
I don't know if I've ever mentioned it here or not, but first time all grain brewers leave my shop with a bag of grain that has 3 ounces of acidulated malt in it. I do it because they don't know about water or mash pH and don't need to be burdened with it on their first brew. I know for a fact that the beer is going to be better that way.

Eventually, maybe by brew 3 or 4, we have a conversation about it and they leave with a bottle of lactic acid and a syringe, but not until they're ready to add that small layer of complexity.

 

[DBhomebrew]

First time all grain brewers leave my shop with

having been served by an owner who cares for their success.

FTFY

 

[AdjunctBrewer]

https://www.homebrewtalk.com/thread...-ph-of-6-extract-tannins.597559/#post-7819359

The suppression of tannin and silicate solubility would be osmotic pressure. The high gravity wort keeps those constituents in the plant matter. When gravity drops, the osmotic pressure favors releasing the constituents into the fluid.

Batch spargers are less prone to incurring this extraction problem. Its continuous spargers that need to pay attention. I'm one of those continuous spargers and I can achieve about 90% system efficiency with my system. While that would seem to be a good thing, I can assure you it is not. Keeping your system efficiency in the low 80's or less, will give you better beer.

https://www.homebrewtalk.com/thread...-ph-of-6-extract-tannins.597559/#post-7819555

Yes. As I've found, even with perfect pH and temperature, you can impart a high dose of tannins and silicate to your wort if you don't plan on cutting your runnings off at a higher than the brewing lore quotes. I've seen a cut off gravity of 2 Brix in many brewing books, but I can't do that with my system and grist. 4 or 5 Brix is safer for me.

 

[AdjunctBrewer]

https://www.homebrewtalk.com/thread...-ph-of-6-extract-tannins.597559/#post-7817781

Although they play a role,temperature and pH are not the primary factors in tannin extraction. The most important factor is the specific gravity of the wort surrounding the grain. As noted, decoction does not typically result in tannin extraction, even though the mash is boiled. The reason is that the wort gravity is high at that stage. The primary means of tannin extraction is during sparging when the wort gravity falls. Being too efficient during sparging and ending with too low a wort gravity will extract tannins into the wort...no matter if your pH or temperature were within recommended range.

https://www.homebrewtalk.com/thread...-ph-of-6-extract-tannins.597559/#post-7818984

Indeed, you folks deserve citations for my contention that the gravity of final runnings is most important.

I start with DeClerck's A Textbook of Brewing, where in the first few paragraphs of Chapter 13 - Filtration of Wort and Spargement of Spent Grain, he presents data and text showing that "last runnings contain abnormal amounts of undesirable matter". The data in the associated table for that passage shows that Ash and Silica increase by 100 to 300 percent. DeClerck goes on to cite Reichhardt who states that final runnings have higher tannin (polyphenol) content. Unfortunately, that Reichhardt reference is not identified in the 1957 version of the textbook, so I couldn't review that Reichhardt reference myself. I'll take the word of a brewing giant (DeClerck), that final runnings also have higher tannin content.

I follow up with information presented in Malting and Brewing Science by Briggs, Hough, Stevens, and Young. Subchapter 9.8 on Polyphenols states that the quantities of polyphenols extracted, increase as wort pH and temperature increase. It goes on to state that the polyphenol proportion increases in the last runnings, to the detriment of the flavor and stability of the beer. The subchapter also distinguishes between 'oxidized' and 'oxidizable' polyphenols and the fact that oxidizable polyphenols can pass into the beer and become tannins and produce haze.

In subchapter 9.18 of Malting and Brewing Science, Sparging is discussed. The effects of increased pH and temperature are correlated to conditions that extract more polyphenols and silicates from grain. But they note that the wort pH rises 0.2 to 0.7 units during sparging in their trials. What I feel is the most important information in this subchapter, is the chart in Fig 9.15 that shows the pH, ash, and silica content of the runoff rise as the sparge continues. An important distinction is that we know that proper pretreatment of sparging water gives us a liquor that doesn't produce a rise in wort pH. I have repeatedly found that even when acidified sparging water is used at temperatures of less than 170F, extending the sparging and driving the runoff gravity below 4 Brix does result in tannin and silicate in the resulting beers. So, I find that it is final gravity of the runnings has the greatest effect on tannin and silica extraction.

 

[DBhomebrew]

Martin's talking about a sparge which reduces SG over time and notes in your quoted snippet that batch sparging doesn't confront the same risk as continuous sparging. The pressing of a batch sparged grain ball doesn't reduce the SG.

 

[AdjunctBrewer]

Martin's talking about a sparge which reduces SG over time and notes in your quoted snippet that batch sparging doesn't confront the same risk as continuous sparging. The pressing of a batch sparged grain ball doesn't reduce the SG.

Batch spargers are less prone to incurring this extraction problem.

Exactly! But what does "less prone" actually mean?

 

[doug293cz]

Exactly! But what does "less prone" actually mean?

Conventional wisdom for fly sparging says to cut off the lautering when the runnings SG gets below about 1.010 (2.5 Plato/Brix.) With a single batch sparge, sparged runnings will typically be in the range of 1.020 - 1.030 (5 - 7.5 Plato/Brix), depending on the end of mash SG. So, per @mabrungard , batch sparging SG typically stays above the 4 - 5 Plato/Brix limit he suggests for minimizing tannin and silicate extraction.

However, if doing multiple batch sparges, the final runnings SG could end up below the 4 Plato/Brix limit, if the pre-boil SG is at the lower end for beer wort.

Brew on

 

[toxdoc49]

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.

I have been using BIAB for several years. This thread is perhaps one of the most useful I have seen for BIAB on this forum. I am no expert but there is a lot of useful discussion in this thread for BIAB. As for myself I do a dunk sparge after mashing, if only to get back to full boil volume. I also use a water temp between 170-180 F to mash out. Maybe it doesn't add much sugar to the wort, but my main interest is getting the full boil volume for the boil as I lose on average 1 gallon from grain mashing in BIAB.

 

[k-daddy]

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).

This is what I do now... hoist the Wilser bag and hang it over a brew bucket until no more drips, then dump the captured wort into the kettle. I'm done with bag squeezing... happy to drop that small but slightly tedious step from my brew day regime.

 

[AdjunctBrewer]

So, per @mabrungard , batch sparging SG typically stays above the 4 - 5 Plato/Brix limit he suggests for minimizing tannin and silicate extraction.

However, if doing multiple batch sparges, the final runnings SG could end up below the 4 Plato/Brix limit, if the pre-boil SG is at the lower end for beer wort.

The grind to dust (grind till your scared, etc...) practice in BIAB might also play a role in tannin extraction especially if the husks are ground to a powder (corona type mill, roller mill w/ too small of a gap) as opposed to left whole (roller mill with correct gap).

There doesn't seem to be any formal studies on BIAB tannin extraction vs grind, SG, pH and temperature - and how one variable affects the others - most just go by pH and temperature constraints. (As opposed to the informal "I always grind till I'm scared and haven't noticed anything...")

 

[doug293cz]

The grind to dust (grind till your scared, etc...) practice in BIAB might also play a role in tannin extraction especially if the husks are ground to a powder (corona type mill, roller mill w/ too small of a gap) as opposed to left whole (roller mill with correct gap).

There doesn't seem to be any formal studies on BIAB tannin extraction vs grind, SG, pH and temperature - and how one variable affects the others - most just go by pH and temperature constraints. (As opposed to the informal "I always grind till I'm scared and haven't noticed anything...")

Something to consider with husks, is that they are thin membranes, and as such, there are very short diffusion distances for water to penetrate and compounds to leach out - if they are going to. Also, because husks are thin, the surface area does not increase much if they are shredded. I doubt husk shredding plays a determinative role in tannin extraction, and that temp, pH, and osmotic pressure play much larger roles.

Brew on

 

[Bobby_M]

I have been using BIAB for several years. This thread is perhaps one of the most useful I have seen for BIAB on this forum. I am no expert but there is a lot of useful discussion in this thread for BIAB. As for myself I do a dunk sparge after mashing, if only to get back to full boil volume. I also use a water temp between 170-180 F to mash out. Maybe it doesn't add much sugar to the wort, but my main interest is getting the full boil volume for the boil as I lose on average 1 gallon from grain mashing in BIAB.

The follow up question is whether you could increase the starting water by 1 gallon to make up for the absorption in advance? That's what most full volume mashers do; anticipate all the losses and built that in to the water calculation. The reason for NOT doing that is that your kettle is too small to accommodate that extra gallon up front, once the grain is added.

 

[AdjunctBrewer]

Something to consider with husks, is that they are thin membranes, and as such, there are very short diffusion distances for water to penetrate and compounds to leach out - if they are going to. Also, because husks are thin, the surface area does not increase much if they are shredded. I doubt husk shredding plays a determinative role in tannin extraction, and that temp, pH, and osmotic pressure play much larger roles.

Brew on

Something to think about:

https://www.homebrewtalk.com/thread...y-astringency-discussion.598719/#post-7836463

For what it's worth, the textbooks used by the German brewing universities like Narziss and Kunze all caution against shredding the husk because it releases a larger quantity of undesirable enzymes like LOX and PPO which can then work to create increased quantities of staling compounds, which can also be astringent. They go through significant lengths to keep the husk intact via processes like steam conditioning, and sometimes even strip away the worst offending parts of the husk like where the arcospire attaches because they contain the greatest concentration of the bad enzymes. But most American craft breweries and homebrewers pay little to no attention to any of that.

 

[North_of_60]

The thread that never dies. Good write up.

I BIAB for 4 reasons:
1. Its all grain
2. It makes great beer
3. The initial cost is minimal
4. I'm lazy, but not lazy enough for extract

I keg for 1 reason:
1. I'm lazy

I ferment in the keg for 2 reasons
1. Cost, I already have the kegs
2. I'm lazy

So bottom line, I'm cheep and lazy.

 

[doug293cz]

Something to think about:

https://www.homebrewtalk.com/thread...y-astringency-discussion.598719/#post-7836463

This is an "appeal to authority" argument, which is one of the common logical fallacies. Do any of those textbooks present real data that compares intact husks to shredded husks to powdered husks w.r.t. to undesirable enzyme concentrations, or tannin, silicate, etc. concentrations, or references to such data? I would be interested in the research that supports the German practices. I prefer to be data driven, not just opinion driven.

With that said, I do not have any measurement data that supports my argument. My argument is based on well established diffusion science, and assumes that diffusion rates are not a function of direction in the husk material, which could be a false assumption (but seems reasonable, at least until contravening evidence is available.)

Brew on

 

[InspectorJon]

They go through significant lengths to keep the husk intact via processes like steam conditioning, and sometimes even strip away the worst offending parts of the husk like where the arcospire attaches because they contain the greatest concentration of the bad enzymes

How would any home brewer ever do that? I can’t prove it but I feel like there must be a lot of other more significant processes we could work on improving before going down the manipulation of barley husks rabbit hole.

 

[AdjunctBrewer]

How would any home brewer ever do that? I can’t prove it but I feel like there must be a lot of other more significant processes we could work on improving before going down the manipulation of barley husks rabbit hole.

That quote isn't from me, it's from a LODO guy named Techbrau in the linked thread.

Dehusking barley at the commercial level is a fairly common operation.

For the homebrewer it would probably suffice to condition the grain before milling.

Do any of those textbooks present real data that compares intact husks to shredded husks to powdered husks w.r.t. to undesirable enzyme concentrations, or tannin, silicate, etc. concentrations, or references to such data?

That's my question also as I don't own those texts.

With that said, I do not have any measurement data that supports my argument.

Well sure, that's why I've asked for any studies done on the subject in #401.

 

[Barão]

Can I make BIAB in the Brewzilla automatic pan ? Would the grain bag be inside or outside the malt basket?

 

[JohnDBrewer]

There's a local brewery where I live and they use a mash press. The grain is completely pulverized, finer then flour by the looks of it. When the mash is complete they run it through the filter. They make good beer and are a big player in the local market. The brewery says their efficiency is in the high 90%. Not sure if they strip the hulls before the grind it to dust. Next time our club has a meeting there I'll get more info. I had never or heard of anything like it so really didn't know what questions to ask. Here's the link to the system.

https://www.brewmation.com/brewing/mash-press

 

[Closet Fermenter]

Can I make BIAB in the Brewzilla automatic pan ? Would the grain bag be inside or outside the malt basket?

I have not done a full biab. I have done a couple full volume mash runs in a Digiboil. This is a 1st generation, 110v unit I got cheap on clearance. I used it, as designed, to heat water. Then, I bought the mash upgrade kit, (again, on clearance), that included a false bottom, malt pipe, and ring to sit the malt pipe on while draining.
The first batch, I just put the grains into the malt pipe. I only had a very small amount of grain escape the pipe and get through the false bottom, but I was a little concerned about scorching.
The next batch, it occurred to me to use my bag inside the malt pipe. I should mention that I am using a corona mill, so I do get some portion of really fine grist in my mash. Wow! Talk about clear, clean wort coming out! I still hit my target OG, so I plan to continue to do this whenever I have a small enough grain bill to fit my unit.
I have done a fly sparge when I didn’t have quite enough room for a full volume mash.
I would think that if you put it outside the malt pipe, it would be about the same thing, but maybe a little awkward to deal with. I would be careful to avoid letting it contact the bottom where it could melt. A false bottom should prevent that.

 

[Closet Fermenter]

Can I make BIAB in the Brewzilla automatic pan ? Would the grain bag be inside or outside the malt basket?

I suppose the real question is should we use the malt pipe at all? There’s a lot of water that surrounds the malt pipe, and on my early model, there’s no pump for recirculating. I can do it manually with a small pot, (I have actually done this), or could hook up an external pump. I could get more grain in there if I ditch the malt pipe. The advantage of the pipe is that it rests on top and drains. I guess the bag sitting on the false bottom is about the same thing.

 

[Halfakneecap]

Can I make BIAB in the Brewzilla automatic pan ? Would the grain bag be inside or outside the malt basket?

Yes, take the malt basket out, but leave the false bottom in. I used to do that in my Robobrew for double batches

 

[Halfakneecap]

I suppose the real question is should we use the malt pipe at all? There’s a lot of water that surrounds the malt pipe, and on my early model, there’s no pump for recirculating. I can do it manually with a small pot, (I have actually done this), or could hook up an external pump. I could get more grain in there if I ditch the malt pipe. The advantage of the pipe is that it rests on top and drains. I guess the bag sitting on the false bottom is about the same thing.

Yes, or you can use clamps to hold the bag up off the bottom, but i found the false bottom is fine. Id stir it a few times through the mash, and id still recirc.

I ended up getting the extension kit for the 35L robo, and now do doubles using the pipe. But before i did that i could get a double batch by using the bag. It was a tight squeeze, and could only work with lower gravity beers ( 1.038 or less ) unless i added sugar to the boil, but it was possible.


I take the central overflow pipe out on my robo, and use a SS bolt to fill the hole. I never fill to that point and it gets in the way for me.

 

[brewmanStan]

Well, I never intended to get involved with this, but I guess maybe it's time. I've never used any other method than all-grain BIAB, and I've always used my own recipes except for the initial wheat ale kit I bought to get my feet wet, and all in my kitchen, on an electric range top. Back when I started, BIAB brewers were still getting hammered pretty bad about the way we brewed. Personally, after well over 100 successful batches of beer in as many tries, I don't care what anybody thinks about my method, and when I say my method, it's because I've adjusted into a comfort zone over time that's not exactly like the book. Works for me, and best of all, my friends and family love the beer I make, and constantly tell me it's better than anything they can buy at the store. I don't let all that go to my head. It simply tells me I'm doing it right. I mostly brew 4 gallon batches but I have occasionally brewed one and three gallon batches. BIAB is the easiest and least expensive way to get into all grain brewing. I wouldn't know how to do it any other way, and I wouldn't even know how to use a malt extract.

 

[MaxStout]

Well, I never intended to get involved with this, but I guess maybe it's time. I've never used any other method than all-grain BIAB, and I've always used my own recipes except for the initial wheat ale kit I bought to get my feet wet, and all in my kitchen, on an electric range top. Back when I started, BIAB brewers were still getting hammered pretty bad about the way we brewed. Personally, after well over 100 successful batches of beer in as many tries, I don't care what anybody thinks about my method, and when I say my method, it's because I've adjusted into a comfort zone over time that's not exactly like the book. Works for me, and best of all, my friends and family love the beer I make, and constantly tell me it's better than anything they can buy at the store. I don't let all that go to my head. It simply tells me I'm doing it right. I mostly brew 4 gallon batches but I have occasionally brewed one and three gallon batches. BIAB is the easiest and least expensive way to get into all grain brewing. I wouldn't know how to do it any other way, and I wouldn't even know how to use a malt extract.

I remember BIAB having an image problem of sorts several years ago when I started doing it, but I think the stigma is long gone now.

Glad to hear you are having successful batches.

 

[bwible]

I mostly brew 4 gallon batches but I have occasionally brewed one and three gallon batches.

I mostly brew 3 gallon batches. I’m interested in how you do 4 gallons. What do you ferment in? I’m guessing you don’t use a secondary since nobody makes a 4 gallon anything. Do you bottle all your beer? Or put 4 gallons in a 5 gallon keg?

I’m always curious to learn how others do things.

Thanks!

 

[Bobby_M]

I remember BIAB having an image problem of sorts several years ago when I started doing it, but I think the stigma is long gone now.

For the most part, I think we've turned the corner. For many of the older members of our hobby, not necessary age "old", but people brewing for 2 decades or more, tend to have a harder time understanding the process (or accepting its viability). The irony of it all is that it's really the only method I could see myself carrying into my later years.

 

[mac_1103]

If it wasn't for BIAB I'd have stuck to extract.

 

[Willy]

If it wasn't for BIAB I'd have stuck to extract.

Or a small grain bill, in hop socks, in a mixed batch. That's how I morphed into all grain, BIAB.