Technique for measuring mash pH

[Rob2010SS]

This is probably going to be a very short discussion but I have a question in regards to measuring mash pH and how/why to do it a certain way.

My standard practice has been to pull a sample at about 15-20 minutes into the mash and again at 45 min into the mash. I keep a couple of shot glasses in the freezer and I transfer the sample back and forth between 2 chilled shot glasses until I get it to room temp, or at least close to room temp (80-85*F is about the highest I'll check at).

I see a lot of social media posts on Instagram where people are sticking their pH probes directly in the mash and checking at mash temp.

-What is the reasoning for checking directly in the mash, if there is any?
-The probes with the ATC feature on them, are they resistant to damage at mashing temps?
-What does the ATC feature actually do - compensate for the higher temp and adjust to show what the pH is at room temp?

I don't plan to start sticking my pH probe in the mash. This is more for curiosity and knowledge on my part.

 

[Oginme]

The reason to stick your pH probe directly into the mash could be either laziness, ignorance of the damage the heat does to your pH probe, or you get a perverse enjoyment in buying replacement pH probes on a frequent basis.

The ATC feature on a pH meter compensates for the change in electrical current from the probe due to the temperature of the fluid the probe is immersed in. This maintains the calibration slope of the probe from the original calibration.

What it does NOT do is give you a pH reading that you would get at room temperature when you are reading hot wort. The changes in pH from hot to cold is dependent upon the ionic content and the buffering mechanisms of the fluid being read.

 

[Robert65]

ATC only allows the meter to auto calibrate, so you don't have to manually set the temperature and offset (you'll notice that calibration solutions come with a chart of their pH at various temperatures.) It isn't meant to compensate for the sample temperature, and no probe is happy or long lived at high temperatures. And since the actual mash pH is displaced at higher temperatures -- the mash chemistry changes, with more hydrogen ions liberated -- and the standard reference temperature when citing pH is room temperature, you want to measure at room temperature. (There are some popularly circulated "corrections" for temperature, but they're all wrong, and the displacement is unique to and dependent on each specific mash composition.) So there is no good reason for sticking your meter in the mash, but then again there's no good reason for a lot of stuff you see posted on social media. And finally, I bet this isn't a short conversation. There's been confusion and misinformation about this in homebrew circles for ever.

 

[bracconiere]

i'm a mash sticker...my MW-101's probe has lasted me 5 years.....(is getting inconveniently slow these days though) my last Ph meter only lasted a couple months though....why i got a meter with manual calibration, and a replaceable probe....


come'on now, you know i had to post in this thread!

 

[Yesfan]

Subscribed, because I don't think this will be short lived either.

 

[bracconiere]

if you want my hard core stick it in the mash meter here it be:

https://www.ebay.com/itm/Milwaukee-...475686?hash=item3b2e37bea6:g:39QAAOSwOz5cmosl


thing is die hard, i just keep the probe in tap water too, lol


and i just pulled the trigger on a new probe, 5 years ain't to bad for 50 bucks.....

https://www.ebay.com/itm/Millwaukee-Probe-for-MW100-MW101-MW102-SM100-SM101-SMS102-pH-Meters/183841971414?_trkparms=ispr=1&hash=item2acdd5dcd6:g:lnkAAOSwk1BcwIgS&enc=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&checksum=1838419714144e54803a7bf34c3e8cfb4b283774efe9


(and for the record, my first meter had auto calibration, and that's what stopped working....that's why went manual with this one)

 

[mabrungard]

I've had a MW-101 for about 15 years and can attest that the probe is a robust component. Important features of a robust pH probe is a double-junction and I think that the gel electrolyte in the Milwaukee probe also helps. But treating the probe well by not exposing it to elevated temperature and keeping it stored in a proper storage solution will also help.

Take a look at this article for some guidance. https://www.brunwater.com/articles/ph-meter-recommendations

PS: there are a lot of articles in that section that you might enjoy.

 

[6Tap]

Well, I learned something here today.

I will be making some changes to my ph reading process and see if I get different results.

Thanks for the info peeps! [emoji482]

 

[RPh_Guy]

I see a lot of social media posts on Instagram where people are sticking their pH probes directly in the mash and checking at mash temp.

That's really weird. Usually the people on Instagram know exactly what they're doing.

 

[day_trippr]

Folks might want to check their pH meter specifications for the scope of ATC - if present - because it's quite often limited in range well below mash temperature...

Cheers!

 

[Rob2010SS]

That's really weird. Usually the people on Instagram know exactly what they're doing.

Hahaha, I thought the same thing!!! Weird...

 

[Robert65]

Folks might want to check their pH meter specifications for the scope of ATC - if present - because it's quite often limited in range well below mash temperature...

Cheers!

This^^^^

My meter's specified operating range (for ATC and any other consideration) extends only to 122°F.

 

[Alex4mula]

I assumed the ATC is not big range. So my basement is usually around 63-64F when brewing so I try to get the sample to at least in the high 70s to low 80s before I measure.

 

[Silver_Is_Money]

There are a multitude of meters with solid state pH probes (with no glass membrane). This one claims to be usable at up to 250 degrees F. (and down to -5 degrees F.).

https://topac.com/phisfet2.html

https://www.mt.com/us/en/home/products/Process-Analytics/pH-probe/non-glass-ISFET-electrode.html

This one even claims to never require calibration,and to not require wet storage:

https://www.labmanager.com/how-it-works/a-calibration-free-dry-storable-ph-meter-10817

https://innovation.ox.ac.uk/success-stories/passing-acid-test-senova-systems/

 

[Silver_Is_Money]

 

[Silver_Is_Money]

Note: Senova Systems is no more. It was bought out by Parker Hannifin.

 

[dmtaylor]

I've been sticking my cheap Chinese pH meter into the mash at ~150 F for the past couple years. It still calibrates fine. Not broken yet. I have measured mash temp vs. room temp and found the difference to be 0.25 -- i.e., to translate from mash temp to room temp I simply add 0.25 -- e.g., 5.15 at mash temp equals 5.40 at room temp. Many past posts from yours truly in this regard. YMMV

 

[day_trippr]

That's kind of restating the point being made wrt using unadjusted data taken at mash temperature...

Cheers!

 

[bracconiere]

Subscribed, because I don't think this will be short lived either.

LOL, i figured i'd wait to say that.... and i'm glad i haven't been the only admitted mash sticker here...

 

[Yesfan]

LOL, i figured i'd wait to say that.... and i'm glad i haven't been the only admitted mash sticker here...

Well, not so much that. I'm just hoping this turns into a plethora of information that I somehow missed and/or didn't know. I'll be honest. Water chemistry is a bit intimidating to me. I have Brun' Water and Beersmith seems to have a decent adjuster, but I don't play around them much. I have a cheap Ph Doctor meter I use. I don't use it every brew session. When I do use it, I mainly just collect a small sample of wort right after doughing in, measure the Ph, and make a note of it on my recipe print out. I don't have an assortment of brewing salts to make adjustment/corrections. My water 'adjustment' mainly is throwing in a campden tablet in my filtered water when I think I need it.

 

[day_trippr]

There are a multitude of meters with solid state pH probes (with no glass membrane). [...]

Wowee zowie! Those meters exist in some rarefied atmosphere!
I built my single tier stand - including the steel, casters, kettles, pumps, chiller, valves, fittings - for less than what even the least expensive model + probe costs...

Cheers! ("Pass" )

 

[dmtaylor]

Well, not so much that. I'm just hoping this turns into a plethora of information that I somehow missed and/or didn't know. I'll be honest. Water chemistry is a bit intimidating to me. I have Brun' Water and Beersmith seems to have a decent adjuster, but I don't play around them much. I have a cheap Ph Doctor meter I use. I don't use it every brew session. When I do use it, I mainly just collect a small sample of wort right after doughing in, measure the Ph, and make a note of it on my recipe print out. I don't have an assortment of brewing salts to make adjustment/corrections. My water 'adjustment' mainly is throwing in a campden tablet in my filtered water when I think I need it.

If your beer is turning out good, I say more power to you! The less fuss the better in my opinion. Cheers.

 

[bracconiere]

If your beer is turning out good, I say more power to you! The less fuss the better in my opinion. Cheers.

i just know if i turn my dial on the meter to a temp correction of 60c, and hit a 5.3 ph in my mash at mash temp...i get the best efficiency....i really don't care if it's accurate or not.....

i've played around with everything between 5.1-5.5ph, 5.3 is the winner, with my meter with it set to 60c, stickin' it in the mash, lol

 

[Silver_Is_Money]

Wowee zowie! Those meters exist in some rarefied atmosphere!
I built my single tier stand - including the steel, casters, kettles, pumps, chiller, valves, fittings - for less than what even the least expensive model + probe costs...

Cheers! ("Pass" )

Maybe someday the price will come down. Did you try Ali-Express or Alibaba for the direct from China pricing?

 

[Yesfan]

Wowee zowie! Those meters exist in some rarefied atmosphere!
I built my single tier stand - including the steel, casters, kettles, pumps, chiller, valves, fittings - for less than what even the least expensive model + probe costs...

Cheers! ("Pass" )

Not to pile on, but I bet your single tier stand didn't get less than 2.5 stars in reviews either.



Hard to justify something that expensive when it doesn't even get decent reviews.

 

[Yesfan]

So, since this is on technique, how often should one check their mash ph? Like I said, I mainly check mine, after doughing in. Are their essential ingredients one should have on hand if adjustments need to be made? I'm sure acidulated malt and/or lactic acid is one of them.

 

[Robert65]

I personally don't try to adjust pH once I've mashed in. I plan my grist and water treatment, check to confirm I'm near target around 15 minutes in, take notes, and use the information to further dial in my process in the over time. Some track pH through the mash, but I find that the pH established early on holds fairly steady right through the sparge and into the kettle. That's all probably another can of worms, but after tracking pH through the whole process for a hundred batches or so, I was satisfied that it doesn't really change significantly, and once established is difficult to shift, and just let it ride.

 

[Robert65]

Since this is a thread about technique, I'll throw another thing out there for discussion: when calibrating, rinse with buffer or DI water between steps? Pros and cons of each? I've seen both recommended by manufacturers, even both by the same manufacturer in apparent self contradiction. Using DI water would certainly save on buffers, but how adversely affected is the calibration?

 

[day_trippr]

I check at 30 minutes, chilled to 70°F. Way too late to chase pH, but about right for record keeping and future adjustment if necessary.
I use the subscriber version of Bru'n Water and as long as I give it good data it gives me good results.

I do rinse the sensor in RO water after measuring (wort or calibration solutions) as I have a convenient RO faucet at my slop sink...

Cheers!

 

[Rob2010SS]

Since this is a thread about technique, I'll throw another thing out there for discussion: when calibrating, rinse with buffer or DI water between steps? Pros and cons of each? I've seen both recommended by manufacturers, even both by the same manufacturer in apparent self contradiction. Using DI water would certainly save on buffers, but how adversely affected is the calibration?

My Apera PH60 recommends that you rinse the probe in distilled or DI water. I just use RO water and rinse it and then it gets stored in the buffer solution.

 

[couchsending]

It’s never too late to adjust your mash pH... just depends on what you’re trying to accomplish. If you’re tryin to maximize enzyme potential then yeah after 20-30 you’re probably too late (depends on your mash steps) but are you really gonna see that drastic of a difference in efficiency? However depending on your water and your sparge method it might be wise to lower that pH even later in the mash as to not avoid tannin extraction during sparge...

In my book Kettle pH is just as, if not more so, important than mash pH... but that’s a whole different topic.

 

[mabrungard]

Kettle pH is the result of proper mashing pH planning. Mashing pH varies remarkably through the course of the mashing period and its very important to measure pH at least 30 minutes into the mash. When starting with low alkalinity water, mash pH tends to be low initially and it rises with mashing duration. That pH response can be opposite when starting with high alkalinity water. However, the bottom line is that mash pH doesn't really settle into a constant value until 30 to 45 minutes into the mash. Thin water/grist ratios (like BIAB) will see more variation in mashing pH compared to thick mashes.

 

[day_trippr]

It's not difficult to tweak kettle pH once the pre-boil volume has been gathered, much easier than trying to shift a mash...

Cheers!

 

[Robert65]

Kettle pH is the result of proper mashing pH planning. Mashing pH varies remarkably through the course of the mashing period and its very important to measure pH at least 30 minutes into the mash. When starting with low alkalinity water, mash pH tends to be low initially and it rises with mashing duration. That pH response can be opposite when starting with high alkalinity water. However, the bottom line is that mash pH doesn't really settle into a constant value until 30 to 45 minutes into the mash. Thin water/grist ratios (like BIAB) will see more variation in mashing pH compared to thick mashes.

There's exactly the can of worms I expected to pop open. Martin, you and I have both tracked pH throughout a similar, huge, number of mashes, and seen opposite patterns. I see it locking in early, you see significant shifts. I may never figure out why. But either way, are we in agreement that it is probably best to take notes and apply the information to the next brew, dialing in our software and treatments, rather than chase one's tail trying to adjust the pH mid-mash? If so, the individual brewer need only establish a consistent practice, measuring pH at the same point every time, and learning both to manipulate pH with greater certainty, and to correlate it with observed effects on the beer.

 

[Robert65]

It's not difficult to tweak kettle pH once the pre-boil volume has been gathered, much easier than trying to shift a mash...

Cheers!

Yep.

 

[Rob2010SS]

Kettle pH is the result of proper mashing pH planning. Mashing pH varies remarkably through the course of the mashing period and its very important to measure pH at least 30 minutes into the mash. When starting with low alkalinity water, mash pH tends to be low initially and it rises with mashing duration. That pH response can be opposite when starting with high alkalinity water. However, the bottom line is that mash pH doesn't really settle into a constant value until 30 to 45 minutes into the mash. Thin water/grist ratios (like BIAB) will see more variation in mashing pH compared to thick mashes.

Not arguing with you as I know you're more knowledgeable than I am when it comes to mash pH.

However, my last 3 brews I checked 15 min into mash and 45-50 min into mash and the pH has varied no more than .02. Im not seeing very much variation in pH from start to finish. Thoughts?

 

[day_trippr]

I don't measure early enough to know much about pH shift from T0 onward in the mash. I do the two checks at 30 and 60, and looking at the last three brews (all neipas, so not much scope there) there was a consistent .02 rise between them - using a meter with .01 precision.

Next brew I'll do some earlier measurements because now I'm curious...

Cheers!

 

[Robert65]

I consider 0.02 shift (either direction) locked in. 0.2 I'd stop yawning.