Keeping ph in check during mash

[mashdar]

Without calibration??

Yeah. Every year I calibrate it, but first I test it in the 4, 7 and 10 solutions to see what kind of drift it had. So far, they have all read correct. (The meter only has 1 decimal place, hence "within one decimal place" in my other post. I imagine if it was more precise, I'd see some drift.)

I may just be lucky.

Since I'm willing to be ~0.15 points off target*, I haven't had much reason to put extra work into it. Additionally, I'm mostly relying on Bru'n, with the measurement checking for major irregularities. All respect to those who care more about it, though. If I were selling the beer, I'd definitely take more measurements, at higher precision and accuracy. But for my house, I've got plenty to do on brew days : )

*Most of what I've read not only says that 5.1-5.4 is fine, but disagrees about what the ideal value even is. I haven't noticed a personal preference in that range.

 

[Dland]

I guess no one else uses litmus paper any more [; I actually don't check my pH that often, but once in a while I do a batch where I test everything, just to be sure I've not strayed too far off course.

 

[ClaudiusB]

Curious. Do you have any pictures of this?

My first pH meter, 30 years old and still working.
Picture #2 is my regular benchtop pH meter.
Pictures #3 & #4 are the pH controllers. All pH meters/controllers have communication capabilities and transmit data to the brewery controller, including pH probe health.
The dosing pump is controlled by the pH controller in picture #3.

 

[mashdar]

My first pH meter, 30 years old and still working.
Picture #2 is my regular benchtop pH meter.
Pictures #3 & #4 are the pH controllers. All pH meters/controllers have communication capabilities and transmit data to the brewery controller, including pH probe health.
The dosing pump is controlled by the pH controller in picture #3.
View attachment 881073

What size system is that? Pro? Looks fancy!

 

[ClaudiusB]

What size system is that? Pro? Looks fancy!

It's a standard homebrew setup, maybe with a few extra buttons.
"Pro? Looks fancy!" Camera manipulation can do wonders.

 

[YeastFeast]

My first pH meter, 30 years old and still working.
Picture #2 is my regular benchtop pH meter.
Pictures #3 & #4 are the pH controllers. All pH meters/controllers have communication capabilities and transmit data to the brewery controller, including pH probe health.
The dosing pump is controlled by the pH controller in picture #3.

Very cool, thanks for posting....

 

[Indian_villager]

My first pH meter, 30 years old and still working.
Picture #2 is my regular benchtop pH meter.
Pictures #3 & #4 are the pH controllers. All pH meters/controllers have communication capabilities and transmit data to the brewery controller, including pH probe health.
The dosing pump is controlled by the pH controller in picture #3.
View attachment 881073

Are you running all this off PLC+HMI or do you have some other way of bringing the data into something like LabView?

 

[TBA]

I definitely need to get a quality meter. To help justify the cost would using it to also check the swimming pool pH hurt it? It is a salt water pool if that matters. Would it shorten the probe life? Pool pH is in the 7.5 - 8 range before adjustments. Would calibration be different based on the range you want to measure?

 

[ClaudiusB]

Are you running all this off PLC+HMI or do you have some other way of bringing the data into something like LabView?

I utilize distributed logic to minimize the length of long wire runs by employing multiple PLCs. All PLCs communicate through power line Ethernet modules for data exchange. All data goes to the control room for localized monitoring of all processes. The control room is not required to do a brew. HMIs are distributed throughout the brewery and grain processing system for localized monitoring and control.

 

[Zadkiel]

It is a salt water pool if that matters. Would it shorten the probe life?

Not as long as you rinse it after

Pool pH is in the 7.5 - 8 range before adjustments. Would calibration be different based on the range you want to measure?

no, but temperature would. Most pH meters calibrate to 25C and any measurement taken at a different temperature will be innacurate.

(PSA: pH meters claiming ATC or 'automatic temperature compensation' does NOT mean it's correcting the reading to the calibrated temperature, it just means it's capable of taking a pH reading at a different temperature to the one it's calibrated to and it being accurate /at that temperature/ which will still need to be adjusted)

 

[ClaudiusB]

I definitely need to get a quality meter. To help justify the cost would using it to also check the swimming pool pH hurt it? It is a salt water pool if that matters. Would it shorten the probe life? Pool pH is in the 7.5 - 8 range before adjustments. Would calibration be different based on the range you want to measure?

If the sodium concentration is very high compared to the H+ ions, you may see the effect of the sodium error on the measurement.
Check the limit of your pH electrode; most vendors will state the pH range they can cover and may state at what value Sodium Errors also known as alkaline error, begin to occur.
"Would calibration be different based on the range you want to measure?" Based on your pH range, the pH 10 buffer would replace buffer 7.

Always use pH buffers that enclose the pH of your sample.
If the sample has a pH of 6, use buffers pH 4 and pH 7.
If the sample has a pH of 7, use buffers pH 4 and pH 10.
Source: My Hach pH meter manual.

 

[pfabsits]

I definitely need to get a quality meter. To help justify the cost would using it to also check the swimming pool pH hurt it? It is a salt water pool if that matters. Would it shorten the probe life? Pool pH is in the 7.5 - 8 range before adjustments. Would calibration be different based on the range you want to measure?

Swimming pools should be maintained between pH 7.2 to 7.6. The reason is that when you add chlorine into the pool (whether added as a liquid or generated by electrolysis) it will exist in two forms (OCl- and HOCl). It is the hypochlorous acid (HOCl) that is the effective sanitizer. So as pH increases (more alkaline) the hypochlorous acid loses the H+ to become hypochlorite ion (OCl-).

With that said, my wife would always take my pH meter to measure the pools pH. She definitely preferred it to the color cube test in which you try to match the color of the sample with reagent to a graduated color cubes that had the pH value. The downside was that I was the one that would have to maintain the meter and make sure it was calibrated or at least ready to use.

You can use a pH meter for both brewing and monitoring the pH of a saltwater pool. The pH electrode used in the vast majority of meters would be acceptable for both applications. There are some electrode designs based with different glass formulations and junctions that I would not recommend but those tend to be specialized. For example a soil pH meter/probe that uses low temperature glass with an open junction. Not good for brewing. But overall the standard meters in the market will serve you well.

I have my preferences in meters and really comes down to budget. At Milwaukee, current employer, my favorite is the MW106 due to probe condition indicator and ability to see offset and slope but at $400 it is out of reach for many. The MW102 is popular portable pH/Temp meter used in brewing and would do well for both applications. If I had to trouble shoot, the slope and offset can be calculated but takes a little understanding of pH and the voltages that we measure. The MW102 is $163.70.

After that a good quality pH tester will work. From Milwaukee there is the pH55 (0.1 pH resolution) and pH56 (0.01 pH). The have all the bells and whistles for a pH tester but mainly the pH electrode is replaceable.

Please feel free to reach out if you have any questions. The biggest advice that I have when it comes to pH meters is to stick to a reputable brand, preferably one that has an office in the USA that you can contact for support. Amazon has so many imports that are somewhat questionable. I purchased one int he past and can honestly say it was a POS. I did not have a good experience and broke down and bought one at a higher price from a manufacturer that could trust the quality.

 

[RyPA]

Are ph strips frowned upon in the community? Just watched this youtube video and they make a good point, why fuss with the electronic meter and the need to calibrate it repeatedly, when strips will always you give a valid reading? Granted, you are not getting an exact numerical value, but does that matter for homebrew?

 

[dmtaylor]

pH strips are notoriously inaccurate. I just bought some fresh ones and they are WAY off compared with my calibrated meter.

 

[RyPA]

pH strips are notoriously inaccurate. I just bought some fresh ones and they are WAY off compared with my calibrated meter.

Copy

 

[Yooper]

Are ph strips frowned upon in the community? Just watched this youtube video and they make a good point, why fuss with the electronic meter and the need to calibrate it repeatedly, when strips will always you give a valid reading? Granted, you are not getting an exact numerical value, but does that matter for homebrew?

pH is all about an exact numerical value, as it’s a logarithmic scale. What I mean is that each whole number on the pH scale is a 10 TIMES change in acidity or alkalinity. So a different between, say, 5.0 and 6.0 isn’t just a little- it;s a lot. The pH of the 5.0 is 10 times the acidity of 6.0.

For a little info on pH in brewing: https://byo.com/article/the-principles-of-ph/

 

[MaxStout]

Interpreting the strips against a color chart is iffy, at best. What may look like, say a 5.4 could actually be several tenths either side of that. They just don't give the granularity brewers need to make an informed observation.

 

[Cloud Surfer]

I bought a cheap pen type pH meter when I started brewing and am convinced it caused me to brew worse beers than if I didn’t own that piece of crap. It was so inaccurate.

I now have a beautiful Milwaukee pH meter and it’s never more than 0.02 out when I recalibrate it. It is one of my most valued brewing tools.

 

[DuncB]

pH strips are perfect when you can't decide is that starsan in a bottle or PBW.
One acid the other alkali and you get a right answer every time.
But whether the Starsan is in range not so accurate

 

[pfabsits]

If the sodium concentration is very high compared to the H+ ions, you may see the effect of the sodium error on the measurement.
Check the limit of your pH electrode; most vendors will state the pH range they can cover and may state at what value Sodium Errors also known as alkaline error, begin to occur.
"Would calibration be different based on the range you want to measure?" Based on your pH range, the pH 10 buffer would replace buffer 7.

Always use pH buffers that enclose the pH of your sample.
If the sample has a pH of 6, use buffers pH 4 and pH 7.
If the sample has a pH of 7, use buffers pH 4 and pH 10.
Source: My Hach pH meter manual.

For a homeowner I would still recommend pH 7 and 4 for calibration. The swimming pool is slightly alakline being ideally between pH 7.2 ot pH 7.6. That is pretty close to the isopotential point of pH 7.

pH 10 is not a very stable buffer. The carbon dioxide in the atmosphere diffuses into the solution and will cause the formation of carbonic acid which will dissociate into carbonate and hydrogen ions resulting in a decrease in pH.

I actually had a water treatment plant that was reporting a whole pH unit discrepency from the field versus the lab. The people in the filed were storing the probe in groundwater which caused an offset error (>60 mV in pH 7) and slope was very low (85%). The thing was, the slope of the pH electrode was okay but the pH 10 buffer was actually pH 9.5 due to the 10 buffer being bad.

Once they cleaned the probe and calibrated in fresh buffers, the offset and slope were back to values as a new probe. Being a municipality they have to calibrate to pH 7 and 10 since their readings are greater than pH 7 (EPA standard). They now calibrate to three points and monitor the differences between the two slopes. There should be very minor difference between the two slope values so when they see a difference then they know to change the pH 10 buffer.

I cannot speak to other manufacturers but I know where I have worked we use an average slope based on calibration. If calibrating in pH 7 and 4 the line will extend to 10. It wasn't until the high end of the meters that the user has an option to use linear or segmented slope. With a segmented slope the calibration of pH 7 and 4 only impact that section. The slope between 7 and 10 is independent. If it has not been calibrated then segement will use adefault value of 100% or 59.16 mV/pH at 25 oC.

Lastly sodium error can be an issue but it happens at very high pH such as pH 12 or above. The high temperature glass formulation has lower sodium error than general purpose formulation used in standard pH electrodes. Attached is a chart that shows alkaline error of solutions that have 0.1M and 1 M Sodium.

 

[ClaudiusB]

For a homeowner I would still recommend pH 7 and 4 for calibration. The swimming pool is slightly alakline being ideally between pH 7.2 ot pH 7.6. That is pretty close to the isopotential point of pH 7.

pH 10 is not a very stable buffer. The carbon dioxide in the atmosphere diffuses into the solution and will cause the formation of carbonic acid which will dissociate into carbonate and hydrogen ions resulting in a decrease in pH.

I actually had a water treatment plant that was reporting a whole pH unit discrepency from the field versus the lab. The people in the filed were storing the probe in groundwater which caused an offset error (>60 mV in pH 7) and slope was very low (85%). The thing was, the slope of the pH electrode was okay but the pH 10 buffer was actually pH 9.5 due to the 10 buffer being bad.

Once they cleaned the probe and calibrated in fresh buffers, the offset and slope were back to values as a new probe. Being a municipality they have to calibrate to pH 7 and 10 since their readings are greater than pH 7 (EPA standard). They now calibrate to three points and monitor the differences between the two slopes. There should be very minor difference between the two slope values so when they see a difference then they know to change the pH 10 buffer.

I cannot speak to other manufacturers but I know where I have worked we use an average slope based on calibration. If calibrating in pH 7 and 4 the line will extend to 10. It wasn't until the high end of the meters that the user has an option to use linear or segmented slope. With a segmented slope the calibration of pH 7 and 4 only impact that section. The slope between 7 and 10 is independent. If it has not been calibrated then segement will use adefault value of 100% or 59.16 mV/pH at 25 oC.

Lastly sodium error can be an issue but it happens at very high pH such as pH 12 or above. The high temperature glass formulation has lower sodium error than general purpose formulation used in standard pH electrodes. Attached is a chart that shows alkaline error of solutions that have 0.1M and 1 M Sodium.

Thanks for the write-up.