Yet more evidence that commercial brewers do not mash at 5.2 to 5.6 pH ...

[Silver_Is_Money]

Best practice is not to acidify right at the beginning of the boil. You want to conduct at least part of the boil at a higher pH to optimize DMS formation from SMM, and hop utilization. It is necessary to acidify to a level sufficient to give a post boil, chilled wort pH of 5.0-5.2 in order for carrageenan based kettle finings to function, and for proper fermentation performance. Kunze recommends acidification "shortly before the end of boiling."

In Bamforth's "pH in Brewing : an Overview" I found this statement:

Kunze recommends adjustment of wort pH to 5.1 - 5.2 by acidification approximately 30 minutes before the end of boiling, to allow prior time for isomerization to be effected.

I'll have to see if I can find where others of Kunze's lofty status are in full agreement with this. The best way to find out would of course be to acidify one half of a split batch just before heating to a boil, and acidifying the other half with 30 minutes of boil time remaining. Calling Brulosophy...

 

[TheMadKing]

In Bamforth's "pH in Brewing : an Overview" I found this statement:


I'll have to see if I can find where others of Kunze's lofty status are in full agreement with this. The best way to find out would of course be to acidify one half of a split batch just before heating to a boil, and acidifying the other half with 30 minutes of boil time remaining. Calling Brulosophy...

On an episode of master brewers podcast they were interviewing someone lofty (can't remember who) about hops. They were talking about modeling hop utilization and bitterness in whirlpool and dry hopping but they did talk about boil hopping as well. He said something to the effect of

Our studies found that Alpha acids are almost completely isomerized within the first 15-20 minutes after adding the hops, and boiling them for longer is only getting the last 3-5 percent.

This was using spectrometry to measure isomerized AA not sensory.

So his main point was that current hop bittering models are way off and even your 15 minute hop additions are almost fully isomerizing. He was fully in favor of keeping 60 minute additions still because of the other benefits such as antioxidant properties and whatnot.

So that would actually line up with Kunz since he's only worried about isomerization for 30 minutes

 

[Robert65]

In Bamforth's "pH in Brewing : an Overview" I found this statement:


I'll have to see if I can find where others of Kunze's lofty status are in full agreement with this. The best way to find out would of course be to acidify one half of a split batch just before heating to a boil, and acidifying the other half with 30 minutes of boil time remaining. Calling Brulosophy...

I can't find 30 minutes explicitly stated in Kunze, just "shortly before the end of boiling." He does note that the majority of DMS precursor will have been reduced to DMS (optimum pH 5.4 and above according to various sources, this goes much slower at lower pH) in 30 minutes, so there is perhaps a basis there for a "30 minute rule." Certainly acidification should take place no sooner than 30 minutes into the boil.

 

[Silver_Is_Money]

On an episode of master brewers podcast they were interviewing someone lofty (can't remember who) about hops. They were talking about modeling hop utilization and bitterness in whirlpool and dry hopping but they did talk about boil hopping as well. He said something to the effect of

Our studies found that Alpha acids are almost completely isomerized within the first 15-20 minutes after adding the hops, and boiling them for longer is only getting the last 3-5 percent.

This was using spectrometry to measure isomerized AA not sensory.

So his main point was that current hop bittering models are way off and even your 15 minute hop additions are almost fully isomerizing. He was fully in favor of keeping 60 minute additions still because of the other benefits such as antioxidant properties and whatnot.

So that would actually line up with Kunz since he's only worried about isomerization for 30 minutes

Recently someone posted a podcast link (and also a data link) to a guy who is university lab level researching and analyzing the impact of pellet hops, wherein he analytically determined that they isomerize far more quickly and efficiently during the boil than do whole/leaf hops. Perhaps when pellets are in play the acid addition to the boil can be added much sooner than for Kunze, since all of the old whole/leaf hop isomerization data is literally found to be useless with regard to pellets. And all of the IBU calculating software built around whole/leaf research is similarly rendered pretty much useless by pellets also. It doesn't even come close. Perhaps we are referencing the same podcast. ???

 

[Silver_Is_Money]

I can't find 30 minutes explicitly stated in Kunze, just "shortly before the end of boiling."

So even the high level pros can misquote each other.

 

[Vale71]

I can't find 30 minutes explicitly stated in Kunze, just "shortly before the end of boiling."

That is correct. In his own words "kurz vor Kochende".

 

[Robert65]

Okay, slightly off to the side. I am 45 minutes into an all Pilsner malt mash and it is at pH 5.4 (room temperature.) Not where any model would have predicted, but looking at notes, this seems to be about where all my mashes of whatever composition and water treatment end up at this point in time. I recall Martin has suggested that all mashes tend toward this point, but now I think I'm becoming more convinced. All the more reason, as I see it, if this is the case, to stop worrying so much about the mash and concentrate on the chilled wort.

(Edited to clarify reference temperature of pH measurement.)

 

[Silver_Is_Money]

Here is a rather interesting peer reviewed study in which it was concluded that alteration in mash pH had a dramatic impact upon the nitrogen content in the Wort, but apparently on not much of anything else.

The results from the laboratory worts were confirmed in a large-scale test: The nitrogen conditions in the acidified test brews are always increased, a fact that can be proved analytically up to the bottled beer. Mash acidification has no relevant influence on beer pH, colour, bitter units, final attenuation, polyphenols, β-glucane values, wort viscosity, free dimethyl sulphide and foam. Flavour stability, considering ageing components, stability index and organoleptic were not altered by mash acidification. In respect of beer flavour, the tasters reported on differences in the beer character, although this could only be a matter of nuances. In order to evaluate the effects on beer flavour definitely, more trial beers would be necessary.

http://www.lowoxygenbrewing.com/wp-content/uploads/2017/04/reiter_1208.pdf

 

[hopjuice_71]

I'm curious about thoughts on the timing of the kettle acidification. Is the 30 minute thing just about hop utilization and DMS removal?

Seems to me the hop utilization issue isn't much of an issue on the home-brew scale where we are not seeking to eek out a bit more efficiency and save a few dollars. Well, at least I'm not.. ..considering I'm dumping up to a pound of hops in a 5 gallon batch of IPA...at that point a bit more or less doesn't really matter..

Also, isn't DMS less of an issue with (most) malts these days?

Is the recommendation for the timing perhaps a) tuned more to large-scale pro-brewing where efficiency is a big issue and/or b) slightly outdated (or specific to certain malts)?

 

[bob1852]

Here is a rather interesting peer reviewed study in which it was concluded that alteration in mash pH had a dramatic impact upon the nitrogen content in the Wort, but apparently on not much of anything else.



http://www.lowoxygenbrewing.com/wp-content/uploads/2017/04/reiter_1208.pdf

So maybe all those amateur professionals who don't bother messing with mash pH are on to something!

 

[hopjuice_71]

Here is a rather interesting peer reviewed study in which it was concluded that alteration in mash pH had a dramatic impact upon the nitrogen content in the Wort, but apparently on not much of anything else.



http://www.lowoxygenbrewing.com/wp-content/uploads/2017/04/reiter_1208.pdf

I'm glad they summed that up in the end. Its largely an impenetrable read.. ..yikes.

 

[Dustin_J]

I'll have to see if I can find where others of Kunze's lofty status are in full agreement with this. The best way to find out would of course be to acidify one half of a split batch just before heating to a boil, and acidifying the other half with 30 minutes of boil time remaining. Calling Brulosophy...

So even the high level pros can misquote each other.

One of the big challenges here is that these recommendations may change over time as people learn more, discover different trade-offs that need to be balanced, etc. For example, Kunze actually changes his own suggestions if you read through different editions. For example, in the 3rd Edition (2004) he directly notes that "It is therefore of interest to considerably reduce the pH to 5.1 to 5.2". While he mentions that this can be done either during the mash or in the kettle, in this edition he clearly states many of the noted benefits other have mentioned here when directly speaking about mash acidification, and also notes that Alpha-amylase is slightly inhibited by doing so, which further suggests that he's explicitly recommending 5.1-5.2 in the mash.

In the 6th Edition(2019), he unequivocally states that "it is therefore advantageous to lower the pH value to 5.4 - 5.5 when mashing. The Beta-amaylase can be damaged at lower values". Note that I'm 99% sure that the reference to Beta here is a typo/translation error, as there are actually a number of them throughout the book, earlier editions clearly reference alpha (not beta) being inhibited at lower pH values, and numerous other sources note alpha having a higher preferred pH range. Anyway, he then goes on to discuss a number of similar benefits of wort pH in the 5.1-5.2 range, but is fairly unclear about "when" during that discussion, which is interesting. The mash pH, recommendation, though, is direct/clear.

Okay, slightly off to the side. I am 45 minutes into an all Pilsner malt mash and it is at pH 5.4 (room temperature.) Not where any model would have predicted, but looking at notes, this seems to be about where all my mashes of whatever composition and water treatment end up at this point in time. I recall Martin has suggested that all mashes tend toward this point, but now I think I'm becoming more convinced. All the more reason, as I see it, if this is the case, to stop worrying so much about the mash and concentrate on the chilled wort.
(Edited to clarify reference temperature of pH measurement.)

Anecdotally, in the handful of mashes I've started recently tracking pH through, I've noticed that those I targeted/initially hit 5.2 and those I targeted/initially hit 5.4 both seemed to stabilize around 5.4 over time. These have all been step mash schedules >60 minutes (Hochkurz or "Brauwelt"), FWIW, and salts/acid were used initially to target those lower pH values.

Here's something from Kunze (3rd. Ed) that might be relevant. As noted, he discusses targeting pH 5.1-5.2 directly in the mash, but then discusses wort/kettle acidification in addition, stating that "These are all good reasons for a biological acidification at the beginning of mashing. Since the phosphatases release a considerable portion of the phosphates, which which play a substantial role in the buffering, the pH shift is partially compensated. It is also therefore worth acidifying the wort. We will see, however, that the wort acidification should preferably occur at the end of or after wort boiling." He then subsequently restates the optimal pH of 5.1-5.2 as the target during wort production, which seems to suggest that one may need to "re-acidify", presumably because the mash pH will creep up a bit. I'll freely admit that I don't understand the chemistry well enough to state that is the case absolutely, but it's some food for thought.

 

[hopjuice_71]

Ok, this just made me really confused: https://www.tandfonline.com/doi/pdf/10.1094/ASBCJ-64-0029?needAccess=true

What do you make of this: "Various factors were examined to determine their impact on the rate of isomerization of α-acids (humulones) to iso-α-acids (isohumulones) during kettle boiling. A model wort boiling system was used that employed multiple 12-mL stainless steel vessels to heat samples (α-acids in an aqueous, pH-buffered solution with other compounds included as specified) at 100°C for 140 min. Concentrations of humulones and isohumulones were quantified at discrete time points using HPLC. Of the factors tested (glucose, maltose, calcium, and pH ranging from 4.8 to 6.0), none were shown to affect the rate of production of iso-α-acids. While pH had a marked effect on the concentrations of α-acids as measured, the differences may be attributed to solubility issues (since the solubility limit was approached and exceeded) that did not appear to affect the rate of iso-α-acid production."

Edit: sorry, as relevant to kettle acidification and hop utilization..

 

[dmtaylor]

Okay, slightly off to the side. I am 45 minutes into an all Pilsner malt mash and it is at pH 5.4 (room temperature.) Not where any model would have predicted, but looking at notes, this seems to be about where all my mashes of whatever composition and water treatment end up at this point in time. I recall Martin has suggested that all mashes tend toward this point, but now I think I'm becoming more convinced. All the more reason, as I see it, if this is the case, to stop worrying so much about the mash and concentrate on the chilled wort.

(Edited to clarify reference temperature of pH measurement.)

A.J. DeLange vehemently disagreed when I suggested this observation that most worts tend toward a common pH. That was a year or two ago. I haven't seen him on here lately.

 

[Robert65]

Something we are also lacking is data on the effect of boiling wort pH on protein coagulation, which will affect the decision on when to acidify. We know that 5.0 is required in chilled wort for kettle finings to work, but remember that while they are added in the boil to dissolve, they only operate in the wort upon chilling, so this does not directly bear on boil pH. We also know that protein solution is aided by lower pH. But coagulation is missing from the picture as far as I can see.

 

[Silver_Is_Money]

One of the big challenges here is that these recommendations may change over time as people learn more, discover different trade-offs that need to be balanced, etc. For example, Kunze actually changes his own suggestions if you read through different editions. For example, in the 3rd Edition (2004) he directly notes that "It is therefore of interest to considerably reduce the pH to 5.1 to 5.2". While he mentions that this can be done either during the mash or in the kettle, in this edition he clearly states many of the noted benefits other have mentioned here when directly speaking about mash acidification, and also notes that Alpha-amylase is slightly inhibited by doing so, which further suggests that he's explicitly recommending 5.1-5.2 in the mash.

In the 6th Edition(2019), he unequivocally states that "it is therefore advantageous to lower the pH value to 5.4 - 5.5 when mashing. The Beta-amaylase can be damaged at lower values". Note that I'm 99% sure that the reference to Beta here is a typo/translation error, as there are actually a number of them throughout the book, earlier editions clearly reference alpha (not beta) being inhibited at lower pH values, and numerous other sources note alpha having a higher preferred pH range. Anyway, he then goes on to discuss a number of similar benefits of wort pH in the 5.1-5.2 range, but is fairly unclear about "when" during that discussion, which is interesting. The mash pH, recommendation, though, is direct/clear.


Anecdotally, in the handful of mashes I've started recently tracking pH through, I've noticed that those I targeted/initially hit 5.2 and those I targeted/initially hit 5.4 both seemed to stabilize around 5.4 over time. These have all been step mash schedules >60 minutes (Hochkurz or "Brauwelt"), FWIW, and salts/acid were used initially to target those lower pH values.

Here's something from Kunze (3rd. Ed) that might be relevant. As noted, he discusses targeting pH 5.1-5.2 directly in the mash, but then discusses wort/kettle acidification in addition, stating that "These are all good reasons for a biological acidification at the beginning of mashing. Since the phosphatases release a considerable portion of the phosphates, which which play a substantial role in the buffering, the pH shift is partially compensated. It is also therefore worth acidifying the wort. We will see, however, that the wort acidification should preferably occur at the end of or after wort boiling." He then subsequently restates the optimal pH of 5.1-5.2 as the target during wort production, which seems to suggest that one may need to "re-acidify", presumably because the mash pH will creep up a bit. I'll freely admit that I don't understand the chemistry well enough to state that is the case absolutely, but it's some food for thought.

My take (the entire premise behind this thread) of course is that, just as for the others of his caliber, Kunze references mash pH at mash temperature, and the subsequent desire to target and achieve 5.1-5.2 pH at the end of the boil as a room temperature measure. It is the only way to make sense of things in light of the universal knowledge that pH falls additionally during the boil. In a falling pH boil environment, why would anyone ever even need to consider additional (and separate) boil acidification for a boil which had been immediately preceded by a 5.2-5.4 mash pH otherwise? I.E, if a low pH has already been established within the mash, and it will inherently fall lower during the boil, why bother with any concern for adjusting via acidification downstream when it should be self evident that 5.1-5.2 pH will be the consequence anyway. But to my knowledge Kunze never makes this (I.E., the temperatures of his mash pH reading references) explicit, perhaps because his professional level audience is presumed to inherently already know this to be mash pH readings at mash temperatures. And my further speculation is that lesser pro level to primarily rank amateur level beer brewing authors very early on combined the valid presumption of the self evidence of boil pH drop in conjunction with a faulty presumption that Kunze and others were all talking about mash pH being measured at room temperature, and then mistakenly concluded that any mash pH brought to 5.2-5.4 at room temperature kills two birds with one stone, thus never having a need (as opposed to that of the commercial brewers) to address downstream Wort pH (and thereby for the most part, if not entirely, simply not ever doing so).

 

[hopjuice_71]

I should probably keep this opinion to myself, because I suspect it won't be popular at all and is only marginally related to the discussion at hand, but here goes...

Knowing what I know about textbooks in general, I view them as only a place to start a discussion. They are typically not a reliable source of the most correct and cutting edge information, and they are often downright wrong. This is irregardless of the fame and respect the authors command. Not to say that textbooks should be summarily discounted, but the primary literature (where protocols are usually, or at least should be, unambiguously reported) is really where one should be looking for answers (and more questions). End rant.

Cheers

 

[Robert65]

My opinion as well. However, the textbooks are the place to start, and they will make you aware of the issues you need to pursue further, and should cite references to begin the process. They are also a useful summary of the current conventional wisdom. If only a standard textbook was the lowest rung on the ladder of homebrew knowledge and discourse, rather than popular homebrew books, magazines, podcasts, etc., which are considered high brow if they even acknowledge the existence of these mere textbooks, the state of things would be greatly improved.

 

[Silver_Is_Money]

I should probably keep this opinion to myself, because I suspect it won't be popular at all and is only marginally related to the discussion at hand, but here goes...

Knowing what I know about textbooks in general, I view them as only a place to start a discussion. They are typically not a reliable source of the most correct and cutting edge information, and they are often downright wrong. This is irregardless of the fame and respect the authors command. Not to say that textbooks should be summarily discounted, but the primary literature (where protocols are usually, or at least should be, unambiguously reported) is really where one should be looking for answers (and more questions). End rant.

Cheers

My favorite peer reviewed document is rapidly becoming the one which concluded that nothing done to change mash pH made any difference in the final beer sans for nitrogen levels. It reminded me of Brulosophy in a way.

 

[hopjuice_71]

My opinion as well. However, the textbooks are the place to start, and they will make you aware of the issues you need to pursue further, and should cite references to begin the process. They are also a useful summary of the current conventional wisdom. If only a standard textbook was the lowest rung on the ladder of homebrew knowledge and discourse, rather than popular homebrew books, magazines, podcasts, etc., which are considered high brow if they even acknowledge the existence of these mere textbooks, the state of things would be greatly improved.

Indeed. My first brewing reference was Brigg's Malting and Brewing Science.. ..but then - mainly as a result of my profession - most people regard me as raging nerd.

 

[hopjuice_71]

My favorite peer reviewed document is rapidly becoming the one which concluded that nothing done to change mash pH made any difference in the final beer sans for nitrogen levels. It reminded me of Brulosophy in a way.

I had exactly that thought when I followed the link you posted and read the paper.

It has occurred to me that if the textbooks were bang on correct then malting and brewing science as a field of research would be dead.

 

[Robert65]

My favorite peer reviewed document is rapidly becoming the one which concluded that nothing done to change mash pH made any difference in the final beer sans for nitrogen levels. It reminded me of Brulosophy in a way.

Except that Brulosophy always obtains such a result for two reasons: 1) they couldn't design and conduct a valid experiment to save their lives, and 2) they set out deliberately intending to show that nothing matters, because their bread and butter is pandering to an audience that only wants to be assured that nothing matters and they can just do whatever sloppy crap they feel like.

 

[Vale71]

My favorite peer reviewed document is rapidly becoming the one which concluded that nothing done to change mash pH made any difference in the final beer sans for nitrogen levels. It reminded me of Brulosophy in a way.

1- AFAIK that is not a peer-reviewed document
2- That is one of the worst papers I've seen so far. Conclusions are drawn but no supporting data is provided except for the Kongress mashes and those actually show that a lot changes with vs. without acidification. For some parameters such as beta-glucans conclusions are drawn but no data is provided at all?!

Conclusions without supporting data = worthless garbage

 

[brewbama]

The “Brülosophy is doing it wrong” argument is prolific here. Yet, I don’t see anyone else providing the same service that Brülosophy does.

In my mind, Brülosophy serves a purpose. They show Joe Six Pack if you follow basic processes, exercise cleanliness/sanitation and other basic “rules”, starch pretty much wants to convert to sugar and yeast pretty much wants to consume that sugar. The results ain’t bad beer. Of course, “ain’t bad” is defined by the drinker.

Deep brewing science in a quest to brew the white whale perfect pint is not for everyone. Some prefer to brew good ole blue collar “ain’t bad” beer. Brülosophy and others show them how. Neither should be condemned by the other. Yet we somehow take offense because “they ain’t doing it right”.

If Brülosophy sux so bad start a similar service demonstrating the “correct way”. I guarantee one thing if you do: you’ll have the “you ain’t doing it right” crowd on you like a chicken on a June bug — just like they’re on Brülosophy.

Now excuse me while I get back to telling this College Football Coach on TV how to call the next play. [emoji851]

 

[SteveH aka shetc]

What a ridiculous set of comments. If for no other reason then that some of their experiments do show significant differences.

Except that Brulosophy always obtains such a result for two reasons: 1) they couldn't design and conduct a valid experiment to save their lives, and 2) they set out deliberately intending to show that nothing matters, because their bread and butter is pandering to an audience that only wants to be assured that nothing matters and they can just do whatever sloppy crap they feel like.

 

[hopjuice_71]

1- AFAIK that is not a peer-reviewed document
2- That is one of the worst papers I've seen so far. Conclusions are drawn but no supporting data is provided except for the Kongress mashes and those actually show that a lot changes with vs. without acidification. For some parameters such as beta-glucans conclusions are drawn but no data is provided at all?!

Conclusions without supporting data = worthless garbage

As far as I can tell, Brewing Science is a bona fide journal with a who's-who of an editorial board and a large group of credentialed external reviewers. No reason to believe this is not peer-reviewed, though the "peers" may be the type that on on retainer for the journal. I agree this is not a well-written article .. at all .. and it likely slipped through the cracks.

 

[hopjuice_71]

The “Brülosophy is doing it wrong” argument is prolific here. Yet, I don’t see anyone else providing the same service that Brülosophy does.

In my mind, Brülosophy serves a purpose. They show Joe Six Pack if you follow basic processes, exercise cleanliness/sanitation and other basic “rules”, starch pretty much wants to convert to sugar and yeast pretty much wants to consume that sugar. The results ain’t bad beer. Of course, “ain’t bad” is defined by the drinker.

Deep brewing science in a quest to brew the white whale perfect pint is not for everyone. Some prefer to brew good ole blue collar “ain’t bad” beer. Brülosophy and others show them how. Neither should be condemned by the other. Yet we somehow take offense because “they ain’t doing it right”.

If Brülosophy sux so bad start a similar service demonstrating the “correct way”. I guarantee one thing if you do: you’ll have the “you ain’t doing it right” crowd on you like a chicken on a June bug — just like they’re on Brülosophy.

Now excuse me while I get back to telling this College Football Coach on TV how to call the next play. [emoji851]

Yeah, Brulosophy gets a lot of hate. When I first started reading the experiments my instincts were to light them up like I would with a harsh peer-review of an article. However, I have ended up defending them as well, and here is why. When I thought about it, I realized that some of the experiments that led to foundational biochemical principles (e.g. the underpinnings of our understanding of metabolism) were far sloppier than what Brulosophy does. With that in mind, surely the Brulosophy experiments may have something to offer?

 

[Bilsch]

Except that Brulosophy always obtains such a result for two reasons: 1) they couldn't design and conduct a valid experiment to save their lives, and 2) they set out deliberately intending to show that nothing matters, because their bread and butter is pandering to an audience that only wants to be assured that nothing matters and they can just do whatever sloppy crap they feel like.

There are times when I wish there was a 'double like' button.

 

[Qhrumphf]

What a ridiculous set of comments. If for no other reason then that some of their experiments do show significant differences.

Pretty sure the few outliers are, ahem, not statistically significant in context.

But, I can agree with the above. Most of their audience doesn't care to delve into the intellectual rigour of this thread (or section). And that's fine. But for most of us it's patently insufficient.

 

[Vale71]

As far as I can tell, Brewing Science is a bona fide journal with a who's-who of an editorial board and a large group of credentialed external reviewers. No reason to believe this is not peer-reviewed, though the "peers" may be the type that on on retainer for the journal. I agree this is not a well-written article .. at all .. and it likely slipped through the cracks.

Slipped through the cracks meaning in this case "no one bothered to read it first"?
I mean, the conclusion states that beta-glucan content is not affected and there isn't a single measurement of beta-glucan levels in the whole dataset the paper is based on? Are we just supposed to trust the author's word on that because they are such nice guys? And the data they've actually bothered to collect (from the Congress mashes only, for reasons that are not stated) actually shows that every measured parameter is affected and rather significantly at that and yet they still claim exactly the opposite in the conclusion?
This goes beyond sloppy work and really borders on dishonesty.