The only real science being done today is called "engineering" anyway. Good enough is always good enough.
The Brew Matrix Experiment #2 - Mash Fines in the Boil x Kettle Trub in the Fermenter
- Thread starter Bobby_M
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But speaking of clearing: did you notice any differences in how fast/how well they cleared?
OP
OP
Two weeks into fermentation. Note that this picture was intentionally overexposed to see if differences could be better seen.
Looking forward to the tasting notes!
So no major difference? Interesting.
I do not think this experiment or trub in general is about beer clarity. It is more about staling over time and any flavor impacts. Most everything settles out over time to produce clear beer. Mashing and boiling are about extracting and leaving things behind you do not want. The boil has a lot of "stuff" that is drawn out of the wort. Logically one would want to leave the stuff in the BK which was kind of the point of the boil. But does it make a difference for the yeast and/or flavor if it makes it into the fermenter? The texts say to leave it behind but it is worth testing to see.
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Yeah, I think the point is that people design systems, and argue endlessly on forums regarding the same, to keep as much particulate matter out of the boil and/or fermenter. This one experiment is for me to see for myself, hopefully backed up by more tasters than just myself, whether more particulates in either of these places reduces the quality of the beer. While I'd like all the beers to taste exactly the same and continue down that same path as the beer ages for a couple months, I'm completely willing to modify my system to accommodate whatever makes better beer.
hungupdown
Well-Known Member
We're gravity readings done by a hydrometer, or refractometer?
Having suspended solids, could increase actual density (as measured by hydrometer). While optical refractometer reading, which measures sugar from refraction angle, I guess wouldn't be affected by solids.
I'll choose my words carefully, but - I really think it does. My readings change, and the line is sharper, if I let my mash sample sit for a few minutes first. I'm not talking about it cooling, but I can see those particles settle out. The readings change and the line is sharper.
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Easydens.
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The tasting happened last night and 19 tasters provided ratings via Google forms so I can manipulate the data relatively easily rather than trying to read handwriting. I'm compiling the responses into more digestible data and will report back soon enough but I just wanted to tease that there were significant differences in the beers in both clarity and flavor.
I did pour a 5th cup "E" that was randomly selected from the four actual variable samples that I used to test for sensory reliability. If a taster rated the duplicate the same as its mate, they get their response slightly amplified. BJCP judges get a rating boost based on their rank as well. I'll show raw and weighted results.
I did pour a 5th cup "E" that was randomly selected from the four actual variable samples that I used to test for sensory reliability. If a taster rated the duplicate the same as its mate, they get their response slightly amplified. BJCP judges get a rating boost based on their rank as well. I'll show raw and weighted results.
Looking forward to the report out!!
Edge of my damn seat
Thanks Bobby. Looks like your setup is working out just as you intended.
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The video is up. I ended up calling this experiment #1 because I never really published any data on the first one and I kind of screwed it up anyway.
Fascinating. Thanks, Bobby.
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For those that TLDR; It SEEMS:
1. An excess of mash fines in the boil may degrade the flavor.
2. Some level of kettle trub (hot and cold break) transferred into the fermenter reduces lag time and helps the beer clear faster and more thoroughly.
The tricky part if figuring out where the threshold is. I forced more mash fines than most people could achieve by accident. I think another run at this is warranted just comparing a typical BIAB process to a vorlaufed dedicated mash tun runoff. The difference in mash fines in the boil would be way more subtle.
As I mentioned in the video, backing off on how fine you mill and reducing the amount of squeezing you do would like be two positive moves. Keep in mind that my pH was in an ideal range. I suspect, very uncontrovercially, that having a high pH in the realm of 5.8+ would make the silty boil sample worse than it was.
On the boil trub in the fermenter topic, I suspect that a very clean wort COULD perform like a trub-heavy transfer with the addition of nutrient and subsequent fining agents. I just don't know why you would do that.
I got to thinking about how one would nudge system design in a positive direction if you were to assume that the cleanest possible boil wort is "best". I'm not saying it is, yet, but let's assume there is no good enough threshold and there's a linear improvement the clearer the wort was in the boil.
For right now, I think it would look something like the Blichmann Brew Easy but with the lower kettle being bottom drained from the center (like the SPIKE Tank). The one detriment to running a Kettle RIMS boil kettle with a side pickup is that the beneficial swirling (for heat distribution) will also cause mash fines to collect in the center of the kettle and never get vorlaufed out. A center bottom drain would ensure that particles exited naturally and then get caught in the mash tun in the filter bed. A stacked kettle design retains the single pump requirement of a typical high end eBIAB setup.
1. An excess of mash fines in the boil may degrade the flavor.
2. Some level of kettle trub (hot and cold break) transferred into the fermenter reduces lag time and helps the beer clear faster and more thoroughly.
The tricky part if figuring out where the threshold is. I forced more mash fines than most people could achieve by accident. I think another run at this is warranted just comparing a typical BIAB process to a vorlaufed dedicated mash tun runoff. The difference in mash fines in the boil would be way more subtle.
As I mentioned in the video, backing off on how fine you mill and reducing the amount of squeezing you do would like be two positive moves. Keep in mind that my pH was in an ideal range. I suspect, very uncontrovercially, that having a high pH in the realm of 5.8+ would make the silty boil sample worse than it was.
On the boil trub in the fermenter topic, I suspect that a very clean wort COULD perform like a trub-heavy transfer with the addition of nutrient and subsequent fining agents. I just don't know why you would do that.
I got to thinking about how one would nudge system design in a positive direction if you were to assume that the cleanest possible boil wort is "best". I'm not saying it is, yet, but let's assume there is no good enough threshold and there's a linear improvement the clearer the wort was in the boil.
For right now, I think it would look something like the Blichmann Brew Easy but with the lower kettle being bottom drained from the center (like the SPIKE Tank). The one detriment to running a Kettle RIMS boil kettle with a side pickup is that the beneficial swirling (for heat distribution) will also cause mash fines to collect in the center of the kettle and never get vorlaufed out. A center bottom drain would ensure that particles exited naturally and then get caught in the mash tun in the filter bed. A stacked kettle design retains the single pump requirement of a typical high end eBIAB setup.
It's interesting that the dirty boil, dirty ferment, scored slightly better than the clean boil, clean ferment. It also appears that a dirty ferment "fixes" a lot of whatever the detrimental effects of a dirty boil are. It also supports the idea that if you are not putting clean beer in the boil (like a lot of BIABers), you should definitely put some boil trub in the fermenter.
It's also interesting that your results align with the much maligned Brulosophy Exbeeriment showing a net benefit of trub in the fermenter when it comes to finished beer clarity, and subtle differences in taste with some tasters preferring the high trub beer, and some preferring the low.
Brew on
It's also interesting that your results align with the much maligned Brulosophy Exbeeriment showing a net benefit of trub in the fermenter when it comes to finished beer clarity, and subtle differences in taste with some tasters preferring the high trub beer, and some preferring the low.
Brew on
Fantastic experiment Bobby, very well done start to finish, including the video, and graphics, of which I appreciate the considerable effort you put into inserting them into the video along with all of the images and other data. I would not have expected the results to be what they were. The most interesting outcome for me is that trub positively affected flocculation. I guess that the trub could contain positively charged molecules that attract the yeast, like how gelatin works. I also find it interesting that the clarity of the final beer correlates so well with its overall rating, when I expected the CBCF beer to be preferred by some tasters since it has yeast in suspension which carries with it hop and malt flavors.
One curiosity I have as the owner of something like 8+ RAPT pills at this point would be the fermentation kinetics. In my experience, both excessive lag times and slow ferments (at any stage) are both independently attributable to an unhealthy fermentation. I would have liked to drop a pill into each fermentor and see what the profiles looked like. Floating hydrometers are poor at absolute measurements of original and final gravity, but they are very good at identifying the different phases of yeast growth, their duration, and slope. I pay attention to these in my fermentations as it tells me whether my pitch rate and fermentation temperatures are appropriate.
Another curiosity I would have as someone that is sensitive to tannins (as mouthfeel) would be whether the bag squeeze samples were worse. Was it a poll option in your survey, or did anyone comment on it at the meet? Personally, I have never had tannin issues from bag squeezing, only from using rice hulls and 'non-dehusked' roasted malts.
I do not have anything but a borderline useless anecdote/speculation to add to this thread. I tend to brew with strains are known to produce more H2S than other strains, including Kolsch, Witbier, Hefeweizen, Augustiner Lager, etc. Some of these I have brewed more than once, and I have observed that a phase I went through obsessing over trub exclusion going into the fermentor anecdotally* (take with several grains of salt) led some of my most "farty" beers. Excluding trub should not, on paper, limit the amount of solubilized cysteine and methionine in the wort from mashing, so I am not sure what in the trub is having the beneficial effect on yeast nutrition and mitigation of this off-flavor, but I have switched to whirlpooling and resting a short time such that a certain 'non-zero' amount of trub makes it into my fermentor, and it seems to result in healthier fermentations coupled with the use of yeast nutrient.
One curiosity I have as the owner of something like 8+ RAPT pills at this point would be the fermentation kinetics. In my experience, both excessive lag times and slow ferments (at any stage) are both independently attributable to an unhealthy fermentation. I would have liked to drop a pill into each fermentor and see what the profiles looked like. Floating hydrometers are poor at absolute measurements of original and final gravity, but they are very good at identifying the different phases of yeast growth, their duration, and slope. I pay attention to these in my fermentations as it tells me whether my pitch rate and fermentation temperatures are appropriate.
Another curiosity I would have as someone that is sensitive to tannins (as mouthfeel) would be whether the bag squeeze samples were worse. Was it a poll option in your survey, or did anyone comment on it at the meet? Personally, I have never had tannin issues from bag squeezing, only from using rice hulls and 'non-dehusked' roasted malts.
I do not have anything but a borderline useless anecdote/speculation to add to this thread. I tend to brew with strains are known to produce more H2S than other strains, including Kolsch, Witbier, Hefeweizen, Augustiner Lager, etc. Some of these I have brewed more than once, and I have observed that a phase I went through obsessing over trub exclusion going into the fermentor anecdotally* (take with several grains of salt) led some of my most "farty" beers. Excluding trub should not, on paper, limit the amount of solubilized cysteine and methionine in the wort from mashing, so I am not sure what in the trub is having the beneficial effect on yeast nutrition and mitigation of this off-flavor, but I have switched to whirlpooling and resting a short time such that a certain 'non-zero' amount of trub makes it into my fermentor, and it seems to result in healthier fermentations coupled with the use of yeast nutrient.
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Yeah, it's really strange stuff. I think that's one thing I said to the group directly following the tasting. Since it was done with Google forms, I saw the trend right away and said, it looks like putting trub into the fermenter is pretty important. The two "clean" ferment samples couldn't catch up in clarity even after 5 weeks in the cold.It's interesting that the dirty boil, dirty ferment, scored slightly better than the clean boil, clean ferment. It also appears that a dirty ferment "fixes" a lot of whatever the detrimental effects of a dirty boil are. It also supports the idea that if you are not putting clean beer in the boil (like a lot of BIABers), you should definitely put some boil trub in the fermenter.
It's also interesting that your results align with the much maligned Brulosophy Exbeeriment showing a net benefit of trub in the fermenter when it comes to finished beer clarity, and subtle differences in taste with some tasters preferring the high trub beer, and some preferring the low.
Brew on
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Admittedly, I took samples and measurements far fewer times than I wanted to. I'm lucky I got the 12 and 24 hour pictures.
No one noted tannins in the general comments on the form or in person following the tasting. This is likely due to the mash pH being 5.3ish across the board. In my humble opinion, I think A was clearly flawed. It was the only one out of the four that I wouldn't drink a pint of.
B and D were extremely close together for me and I rated B a 9 and D an 8 overall. I picked B as the best as it was the most close to a Genesee
| Sample | Aggregate of comments |
| A | Diacetyl, This was my favorite, Something off with this not sure what, This does not taste good, diacetyl, too sweet. |
| B | Clean and Crisp, Acetaldehyde, Hop character highest in this one. |
| C | Low DMS. This is best |
| D | Cleanest. This tastes the best |
Yeah, I'm speculating that you'd want to whirlpool and settle for a short time for the heavier hop particles to be rejected but you wouldn't want to wait like 30-40 minutes for EVERYTHING to settle out.
What struck me most, is that what won out was the current best practice pushed on this forum when I started brewing (about 15 years ago). Way before biab. I (like everyone, it seems like) used 3 vessels with a focus on wort clarity in the vorlauf, then dumped everything but the hops into the fermenters.
Since returning to the hobby almost 2 years ago, with no equipment, I have been biab. The thing I love about it the most is the short brew sessions. I hate to think about opening up my crush--it would add a half hour.
On the other hand, I already use a hlt. I have been thinking about a 2 vessel. This might nudge a reasonable man who isn't completely happy with biab in that direction.
On the other hand, I already use a hlt. I have been thinking about a 2 vessel. This might nudge a reasonable man who isn't completely happy with biab in that direction.
Don't know about that. My impression from years of reading HBT is that the consensus "best process", pushed by many, was clean boil, clean ferment, which came in third here.
Brew on
So the phase I mentioned above was one I went through right after you bent that piece of wire mesh into a circle and I jammed it into the bottom of the Brau to use as a trub dam, ultimately replacing the idiotic mesh filter they equipped it with (side note, I'm glad we didn't weld it in because having it removable makes it way easier to clean).
I had talked to other members of the club at the time who convinced me that "more clear = more better" when it came to wort production. I would whirlpool/chill, pull chiller, whirlpool 20 minutes. Rest 30 minutes, then run off very slowly and leave behind about a full gallon or even better to avoid any chance trub would be sucked in. I also experimented with running everything off, then decanting the beer off the trub the next day when pitching. All of this only had negative effects on my fermentation if any and zero positive effects on clarity.
Nowadays I whirlpool/chill, pull chiller, WP another 2 mins, rest 5-10 minutes, run off full speed and run off everything into the fermentor but the trub pile inside the wire mesh trub dam which is usually still pretty substantial especially if I've done a protein rest or even a low beta rest (where protease and pepsidase still have some low level of activity).
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For all the benefits I believe eBIAB has, and there are many, the one pushback that always gave me some pause was the fines in the boil thing. I certainly do not consider this experiment to be conclusive evidence that all BIAB wort is inferior to 3-vessel wort. At best, I'd say there is evidence that there is an upper threshold of mash fines concentration in the boil that seems to be detrimental. Based on evidence of outstanding beers being produced by the BIAB method, I think that many brewers using the method are operating below the threshold. I will likely repeat this fact many times in the ongoing discussion just to be sure people see it and feel it, but the amount of fines in these boils was at least TWICE as much as the average batch.
Oh, I agree 100%. I'm just always thinking about what I might change on my baling wire and duct tape setup if I ever get a chance. I've made very good beer with a wilser bag and almost nothing. Something about the aesthetic of the semi-consumable synthetic fiber bag has never inspired me, despite its utter functionality.
I don't like the idea of stacking vessels, but I've always liked the look of the blickmann false bottom. I like the idea of the bottom drain that you do with those. I think a custom 2 vessel could be compelling. 120v to preheat/mash and propane to boil, since I'm outside anyway. And a decent mill to get the traditional crush.
A system like that would add 30-60 minutes to my brew day.
Great experiment.
It would be cool to see an overall ranking done in opaque cups. I wonder how much the clarity of D pushed it up its Overall scores. Did you happen to try these in opaque cups? Do you think you could tell differences by taste or aroma alone?
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There was some discussion way up in this thread about the pros and cons of taking the visual away from the tasting. If the focus was only flavor, that would make sense but everyone drinks beer in clear glasses. How does process affect the beer in the glass with all things considered? I'm not suggesting that the clear vs hazy appearance didn't affect the overall rating. It probably did, because it generally does. I have enough of the beer left to have all the club's judges taste them blind next month and I'll publish that data when it happens.
