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

[Vale71]

if it inhibits alpha-amylase, wouldn't that cause it to be more attenuatble? being that beta is what makes it more attenuable... or maybe i'm not understanding what you're saying?

This is a common misconception. Beta-amylase chops off fermentable sugars at the end of the glycosidic chains. Becaus of that the rate at which it operates and how effective it is also depends on the average lenght of the chains in the mash. Since alpha and beta always work together to some extent promoting alpha-amylase up to a certain PH value also indirectly promotes beta activity and thus fermentability.
In practice, increasing PH will promote both alpha and beta together until such a high value is reached that PH starts to directly inhibit beta activity, from that point upwards fermentability will start decreasing again (but conversion will be much faster). The exact values also depend on the mashing temperature and the type of malt as different types have different enzymatic makeup.
Conversely, too low a PH value will directly promote beta activity but also greatly inhibit alpha activity which will make achieving conversion slower and aslo reduce fermentability. It's possible that smaller breweries that are targeting very low PH values (lower than recommended in the literature) might be thus trying to compensate for excessive fermentability at the cost of other drawbacks such as longer conversion times and possibly reduced efficiency and lower hop extraction due to lower boil PH.

 

[Miraculix]

EBC standard 8.17, which specifies post lautering and all stages of sparging and/or run-off "Wort pH" (which is different from Mash pH) does state to take such "Wort pH" readings at 20 degrees C. But it is talking about pH measurements made downstream of the mash. I've searched in vain (so far at least) for either an EBC or ASBC specification for the taking of specifically a mash pH. That such has not materialized indicates to me that there is little commercial interest in establishing such a specification, and my presumption is that this is due to their more pressing concern with fine tuning downstream Wort pH pre-boil such that they achieve 5.0 - 5.2 pH as measured at 20 degrees C. post boil and cooling.

Just a thought:

Doesn't the mash pH @20c give you an incorrect picture on the effect the pH has on the mash?

If we take the mash pH at 20c, we don't know at which temperature the mash is, so it could be easily +-12c. This difference would result in a completely different mash pH at mashing temperature if we would compare the same 20c ph at 60c or 72c mashing temperature.
It therefore would have a different effect on the mash, depending on the actual mashing temperature.

Therefore I would suspect that the mash pH should be read at mashing temperature to really get an understanding on the effect it has on the mash.

 

[Silver_Is_Money]

I won't argue over the pH ranges needed, but I'll hold firm that the pH should be measured at room temperature, if for no other reason but not to cause undue wear on the electrode. Then again, this could be some OCD/anal-retentive trend that has stuck with me from being a lab lackey.

With the pH probes available to home brewers I'm in 100% agreement with measuring mash pH at 20 degrees C., but I believe that for this case the ideal pH range shift due to temperature change must be applied to the readings, and the nominal midpoint target must be shifted upward to closer to 5.6 or 5.65 as opposed to 5.4, and a new range of 5.5 to 5.8 or perhaps 5.5 to 5.9 should replace the 5.2 to 5.6 range which had formerly been presumed to be in relation to room temperature, but which is now clear to me to represent mash temperature (from the perspective of the commercial brewers).

But if one shoots for a "room temperature" targeted 5.6 or 5.65 pH during the mash, one must also acidify downstream just pre the boil step (or perhaps early on in the boil) so as to hit 5.0 to 5.2 post boil and cooling (as measured at 20 degrees C.). For this it seems from the literature that 5.2 presents a bit more lively hop presence, and 5.0 a bit more subdued hop presence, and some beers and/or personal preferences may favor either extreme, or be well suited for 5.1 pH in the middle.

 

[Silver_Is_Money]

It's most likely beacause lower PH would inhibit Maillard reactions which is something you would instead rather like to promote when doing a decoction.

Adjusting pH pre-boil so as to hit a room temperature measured 5.0 to 5.2 pH post boil and cooling prevents runaway Mailiard related reactions caused by boiling higher pH worts, and thereby prevents an undesired and unexpected darkening of the final beer color during the boil.

 

[Silver_Is_Money]

I will admit that bits and pieces of this theme of mine (with the help of those who spearheaded it ahead of me, such as @Robert65, who was my primary initial inspiration) have appeared across a multitude of other threads, but I felt this subject needed consolidation under a single thread for easy reference access.

 

[dmtaylor]

Just a thought:

Doesn't the mash pH @20c give you an incorrect picture on the effect the pH has on the mash?

If we take the mash pH at 20c, we don't know at which temperature the mash is, so it could be easily +-12c. This difference would result in a completely different mash pH at mashing temperature if we would compare the same 20c ph at 60c or 72c mashing temperature.
It therefore would have a different effect on the mash, depending on the actual mashing temperature.

Therefore I would suspect that the mash pH should be read at mashing temperature to really get an understanding on the effect it has on the mash.

Excellent observation.

 

[eric19312]

I will admit that bits and pieces of this theme of mine (with the help of those who spearheaded it ahead of me, such as @Robert65, who was my primary initial inspiration) have appeared across a multitude of other threads, but I felt this subject needed consolidation under a single thread for easy reference access.

Do you think the consensus is there now to create such a thread? I still see a lot of people talking past each other.

 

[dmtaylor]

Do you think the consensus is there now to create such a thread? I still see a lot of people talking past each other.

We won't get consensus until several celebrities jump on board. Only celebrities receive respect from the masses, whether they're right or not. So far all we've got for celebrity support is Ashton Lewis and he's kind of a B-lister.

 

[Robert65]

We won't get consensus until several celebrities jump on board. So far all we've got is Ashton Lewis and he's kind of a B-lister.

Yeah he's not a real homebrew celebrity because he has an actual advanced degree in brewing science from UCD, right? Consensus amongst the likes of Bamforth, Briggs, Kunze, etc. means nothing to homebrewers. If the Brü bros got on board... [emoji38]

 

[Silver_Is_Money]

Just a thought:

Doesn't the mash pH @20c give you an incorrect picture on the effect the pH has on the mash?

If we take the mash pH at 20c, we don't know at which temperature the mash is, so it could be easily +-12c. This difference would result in a completely different mash pH at mashing temperature if we would compare the same 20c ph at 60c or 72c mashing temperature.
It therefore would have a different effect on the mash, depending on the actual mashing temperature.

Therefore I would suspect that the mash pH should be read at mashing temperature to really get an understanding on the effect it has on the mash.

Technically this is spot-on, and mash pH readings should be taken at mash temperature accordingly for the highest precision. But many have observed that budget pH meters longevity is rather seriously negatively impacted by measuring at such elevated temperatures as seen within the mash, so a compensation factor "of sorts" is applied such that a mash pH reading taken at 20 degrees C. can be ballparked to what it might have been had it actually been taken at some nominal mash temperature.

The problem then becomes one of asking "What compensation factor is to be used?". Briggs states that in going from measurement at 65 C. to measurement at 18 degrees C. he observes 0.35 pH points worth of elevation. Palmer states that a similar shift in temperature results in only a 0.25 pH point rise. Sadly, this is not very good agreement. My compromise is to presume 0.30 pH points, ballpark splitting the difference.

For Briggs (if one can presume the slope of the difference in pH with temperature alteration to be linear on first approximation) the difference is one of ~0.00745 points of pH change per degree C. of measurement temperature change (or ~0.00414 pH points of difference per degree F.)

For Palmer the difference is ~0.0056 pH points per degree C, or ~0.0031 pH points per degree F.

Splitting the difference between Briggs and Palmer leads to ~0.0065 pH points change per change in measurement degree C., or ~0.0036 pH points change per change in measurement degree F.

We could come closer to a reliable compensation factor if we could resolve why Briggs witnessed 0.35 points of pH shift vs. Palmer's witnessing only 0.25 points of shift.

 

[Robert65]

Palmer and Kaminski give this formula as an approximation, using degrees Celsius:

pH (room temperature) = pH (mash temperature) + 0.0055(mash temperature - room temperature)

Maybe somebody wants to kick the tires on that.

 

[Die_Beerery]

Yeah he's not a real homebrew celebrity because he has an actual advanced degree in brewing science from UCD, right? Consensus amongst the likes of Bamforth, Briggs, Kunze, etc. means nothing to homebrewers. If the Brü bros got on board... [emoji38]

Actually he's a tool. He's a "technical" editor and "wizard"for a popular home brewing magazine. He was an editor on a paper of mine, where he argued many common knowledge things, including but not limited too, how boiling water does not deoxygenate it.

I agree on all this homebrew celebrity stuff though.

Why doesn't some one go buy an industrial pH probe and put one in process and do some work? I hate all this homebrew hypothesis all the time.

 

[Silver_Is_Money]

Why doesn't some one go buy an industrial pH probe and put one in process and do some work? I hate all this homebrew hypothesis all the time.

I'm in generally poor health (bone marrow cancer, or more specifically polycythemia vera, once but no longer considered in the true cancer family, and now classified more properly as a myeloproliferative disorder), retired, and living on a fixed income. Here's to hoping that you already have such equipment and that you could tell us your preferred mash pH (and/or downstream Wort pH) target plus what temperature you use to take the reading, and the difference you observe between pH readings at 20 degrees C. vs say 65 degrees C.

 

[dmtaylor]

I'm in poor health (bone marrow cancer...

Man..... I was going to "Like" your post, too... Keep your chin up, and know that you are appreciated very much.

 

[ScrewyBrewer]

Why not calibrate your pH meter using solutions at 152F/66.7C and then take a pH reading at 152F/66.7C. Then calibrate your pH meter to 77F/25C and cool the sample taken previously to 77F/25C and take a reading. Then compare the high temperature pH reading to the low temperature pH reading. It seems to be the logical way to test those theories.

 

[Silver_Is_Money]

Man..... I was going to "Like" your post, too... Keep your chin up, and know that you are appreciated very much.

I amended my post above to reflect the current science behind my predicament. I first became aware of my predicament back in 2005 and I'm still here. But it is progressive, and one myeloproliferative disorer can mutate into another..

 

[Miraculix]

Technically this is spot-on, and mash pH readings should be taken at mash temperature accordingly for the highest precision. But many have observed that budget pH meters longevity is rather seriously negatively impacted by measuring at such elevated temperatures as seen within the mash, so a compensation factor "of sorts" is applied such that a mash pH reading taken at 20 degrees C. can be ballparked to what it might have been had it actually been taken at some nominal mash temperature.

The problem then becomes one of asking "What compensation factor is to be used?". Briggs states that in going from measurement at 65 C. to measurement at 18 degrees C. he observes 0.35 pH points worth of elevation. Palmer states that a similar shift in temperature results in only a 0.25 pH point rise. Sadly, this is not very good agreement. My compromise is to presume 0.30 pH points, ballpark splitting the difference.

For Briggs (if one can presume the slope of the difference in pH with temperature alteration to be linear on first approximation) the difference is one of ~0.00745 points of pH change per degree C. of measurement temperature change (or ~0.00414 pH points of difference per degree F.)

For Palmer the difference is ~0.0056 pH points per degree C, or ~0.0031 pH points per degree F.

Splitting the difference between Briggs and Palmer leads to ~0.0065 pH points change per change in measurement degree C., or ~0.0036 pH points change per change in measurement degree F.

We could come closer to a reliable compensation factor if we could resolve why Briggs witnessed 0.35 points of pH shift vs. Palmer's witnessing only 0.25 points of shift.

Just to complicate it a bit further, the pH scale itself is not linear but logarithmic. That's why I think a linear factor per degree might not bare the desired results.

 

[Die_Beerery]

I'm in generally poor health (bone marrow cancer, or more specifically polycythemia vera, once but no longer considered in the true cancer family, and now classified more properly as a myeloproliferative disorder), retired, and living on a fixed income. Here's to hoping that you already have such equipment and that you could tell us your preferred mash pH (and/or downstream Wort pH) target plus what temperature you use to take the reading, and the difference you observe between pH readings at 20 degrees C. vs say 65 degrees C.

Firstly, I am sorry to hear that.

Secondly, I do infact have the equipment and the data. But I am not a homebrew celebrity so no one cares what I have to say.

Thirdly, the answer will probably disappoint everyone.

 

[Silver_Is_Money]

Firstly, I am sorry to hear that.

Secondly, I do in fact have the equipment and the data. But I am not a homebrew celebrity so no one cares what I have to say.

Thirdly, the answer will probably disappoint everyone.

I've always considered you somewhat of a celebrity, plus I'm very impressed with your website and your approach to brewing, and I care about what you have to say. That plus I've been disappointed and gotten over it many times in my life.

 

[zebradeltaone]

He actually told you that? In that case, did he mention at what temperature they measured?

Jon Kimmich had mentioned that before in a talk he gave at a brewer's conference.

 

[cire]

Larry, it saddens me to read of your predicament and having followed your postings for some time. I wish to continue doing so for much time to come and hope your health holds strong for all that time and more. However, on the topic under discussion here, my opinion is not in line with yours.

From my outset in dealings with professional brewers I found hardly any with a grasp of pH, not that I claim to be an expert. Similarly I came across few professional chemists who understood brewing beyond the odd snippet. Most brewers, however, knew when taking a gravity or pH reading to put the sample jar in running water until it had cooled.

To stay in business in the past breweries employed chemists to maintain beer quality, while today more likely to employ a graphics artist to design labels and can art and I would suppose the average head brewer knows any more now than then.

By observation you would seem to have been reading the archives of The Journal of the Institute of Brewing, so might I recommend another?

There, in the earliest days of what today we designate "pH", when that science was in the remit of the chemist and not the brewer, a reference to the then standard temperature of 18C (~65F). On page 411 are some mash readings which, 98 years later, are those expected today with a cooled sample. So did brewers take mash pH measurements out of the hands of the chemists?

I started brewing when pH meters were powered by mains electricity and housed in a laboratory, not handheld with a probe that would reach several feet, passed the sparge arm and into the grain in a mash tun. Then I would use pH strips which, by the time they were in a position to compare with the color chart were cool and if they read pH 5.8 it was certain there was too much alkalinity present in the liquor.

Just my version.

 

[Silver_Is_Money]

To those that want to give high mash pH a try, I say go for it. But my experience is that high mashing and wort pH is the number one cause of the dull beers that we often find from homebrewers and craftbrewers that don't attend to water chemistry adjustment.

This is why if you are going to intentionally mash at a high pH I recommend adjusting to 5.0-5.2 pH pre-boil. I think this sets the hops on the right track and also addresses the high pH and Maillard over-reaction color issue during the boil.

 

[Silver_Is_Money]

By observation you would seem to have been reading the archives of The Journal of the Institute of Brewing, so might I recommend another?

There, in the earliest days of what today we designate "pH", when that science was in the remit of the chemist and not the brewer, a reference to the then standard temperature of 18C (~65F). On page 411 are some mash readings which, 98 years later, are those expected today with a cooled sample. So did brewers take mash pH measurements out of the hands of the chemists?

I started brewing when pH meters were powered by mains electricity and housed in a laboratory, not handheld with a probe that would reach several feet, passed the sparge arm and into the grain in a mash tun. Then I would use pH strips which, by the time they were in a position to compare with the color chart were cool and if they read pH 5.8 it was certain there was too much alkalinity present in the liquor.

Just my version.

Wow, 1921. That was a great read indeed. I'm impressed with how much was known of pH and its impact back in 1921. Particularly since pH was only fully conceptualized in 1909, and that in 1921 the pH meter was still about 13 years down the road. And I'm equally impressed with the level of science that was understood in 1921 with regard to both buffers and brewing. As you said, it more than likely well exceeds the knowledge of most micro-brewers today. Thanks for posting the link.

 

[Die_Beerery]

I've always considered you somewhat of a celebrity, plus I'm very impressed with your website and your approach to brewing, and I care about what you have to say. That plus I've been disappointed and gotten over it many times in my life.

LOL.

My 3 in process pH probes on my system are calibrated at room temp and have ATC. I have one in the HLT, MT and BK. With my system I have the ability to blend water (tap and ro) and since I have a sauergut reactor and automation there I am able to auto dose and nail in any pH I would like. Here is the brewery data screen.

More specifically your answer..

 

[Silver_Is_Money]

Thanks @Die_Beerery! So you target a room temperature measured 5.4 pH in the mash and a room temperature measured 5.1 pH in the boil. Well done. Every aspect of this impresses, and no aspect of it disappoints. Did you ever experiment with higher pH's during the mash?

 

[madscientist451]

Mega brewers have millions of dollars at stake; I'm sure their computer controlled equipment does everything possible to get every last ounce of beer out of a train load of grain...

 

[TheMadKing]

Thanks @Die_Beerery! So you target a room temperature measured 5.4 pH in the mash and a room temperature measured 5.1 pH in the boil. Well done. Every aspect of this impresses, and no aspect of it disappoints. Did you ever experiment with higher pH's during the mash?

Question for either of you

@Die_Beerery you’re measuring at mash temp using a pH probe with ATC calibrated at room temp, correct?

So isn't 5.4 the actual mash temp pH since it's the value displayed after processing by the ATC algorithm? Or does ATC show the "room temperature equivalent" pH?

 

[dmtaylor]

Question for either of you

@Die_Beerery you’re measuring at mash temp using a pH probe with ATC calibrated at room temp, correct?

So isn't 5.4 the actual mash temp pH since it's the value displayed after processing by the ATC algorithm? Or does ATC show the "room temperature equivalent" pH?

I had the same question... but without giving a crap about "ATC" which is misunderstood.

 

[TheMadKing]

I had the same question... but without giving a crap about "ATC" which is misunderstood.

Can you clarify? What does it actually mean if it’s misunderstood?

Edit

Thermofisher says that ATC adjusts the slope of the calibration based on the measured temperature in the sample so that the correct pH is displayed regardless of calibration temperature.

So by that definition, and assuming Die_beerery is using it correctly, and I’m sure he is, the value of 5.4 is the true pH as measured at mash temp

So the pH at room temperature would be higher by some amount (unknowable unless someone has a good model)

 

[dmtaylor]

Brewers being what we are, I'm not going to dare to assume whether the pH is reported at mash temperature vs. room temperature. The pH reading is pretty useless until/unless the applicable temperature is likewise specified by the provider of the data.

As for ATC, at this moment in time I only know enough to know that I don't know what it really does.