Tell me about pH meters

[DVCNick]

Time to stop guestimating my pH numbers.
I see pH meters starting from $10 on Amazon. If those work, great, but I want something that is going to be accurate and reliable and last.

What does everyone use that they believe meets these requirements?
Thanks

 

[balrog]

I suggest you read the sticky on the science forum, as a good start.
Several people use the Milwaukee, several use the $70-90 stick meters

 

[enkamania]

I have the MW102 and have had it for 4 years.

 

[jdauria]

Definitely don't skimp on a meter. Those cheap ones are barely better than using pH strips which are not very accurate. I recommend the Milwaukee MW102 which is a little expensive, or the Thermoworks 8689 which is currently on sale for $79 on their site. I have tried the $40 Beverage Doctor one and, at least the one I had, was junk. Would calibrate it and then take mash pH and it would be nowhere close.

 

[mabrungard]

Here is a start:

pH Meter Recommendations | Bru'n Water

 

[bracconiere]

for $10 it's probably a soil meter.....they don't work for this purpose, ask me how i know!


(i spent $65, a good deal, on a Milwaukee MW-101 back in 2013....i got it because it's a manual calibrating one, my first one was automatic, and it wouldn't calibrate after 3 months...and i spent over ~$150 on the stupid pen thing...of course i bought it at a hydroponic 'pot grower' shop)


my milwaukee still works great.....i need a new probe for it, but only cause i also use it to test crap that dissolves plastic......

 

[jimyoung]

I went the pH meter route first... They're not cheap, the probes wear out, and the thing requires special care (eg probe storage solution). I moved back to ph strips.

 

[mabrungard]

pH strips are notoriously inaccurate and very difficult to read due to the wort coloring the panels. A good manual meter like the MW-101 is less expensive and more reliable since it won't get confused like some of these automatic meters. Do recognize that the probe has a finite life and you WILL have to replace it every few years. I managed to get over 5 years out of my MW-101 probe before it required replacement. At $40 for the probe, that worked out to $8/yr. I'll live with it.

 

[Mikey B]

Okay... so we all know that pH is temperature dependent right? Unless you are measuring pH 7 which has a millivolt reading of zero. That means that the temperature does not matter for pH 7.0 only. It is also a log scale system that only measures H+ ions. Unless you have very stable and or fresh standards you are fooling yourself. Not that I sold pH probes etc. to the pharma industry for 15 years.... yes the meter matters but the probe, standards and knowledge matter more. If you measure pH at different temps all bets are of unless you characterize the exact same wort a number of times. Sorry guys but anything beyond 0.1 accuracy is meaningless. Sorry but this is a sore spot for me. Either store your probe in pH 4 buffer or saturated KCL solution. Potassium Chloride

 

[day_trippr]

Aaaand welcome to HBT!

 

[bracconiere]

Aaaand welcome to HBT!

looks like they've been lurking for quite some time.....just finally got incensed enough about ph meters to make a debut!


And Welcome!

 

[moorejl57]

pH strips are notoriously inaccurate and very difficult to read due to the wort coloring the panels. A good manual meter like the MW-101 is less expensive and more reliable since it won't get confused like some of these automatic meters. Do recognize that the probe has a finite life and you WILL have to replace it every few years. I managed to get over 5 years out of my MW-101 probe before it required replacement. At $40 for the probe, that worked out to $8/yr. I'll live with it.

Given your extensive experience with this topic, if starting with distilled water and adding the appropriate salts and acidulated malt additions, how close would you say the typical calculated mash pH is to the measured pH? I assume the main variable is the malt, but I would like to avoid buying a pH meter if possible. I have not even looked at my brewing water yet and just want to test the waters (pun intended).

 

[mabrungard]

I think several pH prediction programs can get within about a tenth of a unit. The real problem comes when “odd” grains are in the mix.

 

[DVCNick]

Thanks guys. I just got an MW102 on sale from Buckeye Hydro, and have read through about half the other thread and Martin's website.
Based on that I've also ordered bottles of 7 and 4 cal solution, and storage solution. Hopefully that will be enough to keep me going for a while.

My tap water is pretty soft according to the internet DB I saw, and also pro brewers in the area have told me that repeatedly (although I plan to have it tested someday to actually quantify that exactly). Would there be great harm in using that to rinse between calibration points?

Also, it seems that calibrating on every brew day is going to be SOP... everyone recommends it.

For now I'm mostly thinking about checking the mash, but I've seen references to boil pH mattering as well.
Once you have a recipe dialed in and generally repeatable, do you do a pH reading every time, or do you mostly check while getting a recipe dialed in and then trust that it will be the same moving forward once you are happy with it?

Last question for now... if I want to use a shot glass for calibration solution when calibrating, what is the proper way to clean it? Just make sure it thoroughly rinsed with tap water and dried, or is there something else?

 

[day_trippr]

• Definitely calibrate for brew days. "Drift Happens"
• Test and storage solutions have expiration dates. Don't overbuy.
• I use RO from my home system, but if you shake the probe vigorously after rinsing/prior to test (which should be done anyway) there won't be much rinse water left behind regardless.
• I check mash pH at 20, 40 and just before fly sparging, then I check the last sparge runnings, then the pre-boil kettle pH and finally post-boil pH. Every brew. It's my inner and outer engineers taking control
• I use small Sam Adams sample glasses, fwiw, and dry them after rinsing between samples...

Cheers!

 

[DVCNick]

Thanks sir... I read somewhere that the 4.01 solution can work as storage solution in a pinch until my bottle of it gets here? Not even a sample packet of storage solution was included with the meter.

 

[DVCNick]

One more question... I'm not sure if it's my imagination, but I think the liquid level inside the probe has dropped just in the time I've been messing around with it (checking my tap water, starsan, etc) haven't even calibrated it yet, just wondering... is that normal? The documentation that came with it is pretty minimal.

 

[day_trippr]

I'm going to go with "imagination" as the sensor is in a sealed bulb


Cheers!

 

[DVCNick]

I'm talking about the liquid in the shaft rather than the head... (wait, what?)

 

[day_trippr]

"What?" indeed. No idea what you're referring to.
Maybe there's something curious about the mw102 sensor. I have no experience, but there are plenty of users here...

Cheers!

 

[DVCNick]

The liquid level is currently at the arrow. I think it was a little higher when I first took it out of the box, but not sure.

 

[enkamania]

The liquid level is currently at the arrow. I think it was a little higher when I first took it out of the box, but not sure.

I never looked at that until today, mine looks full. Reach out to the manufacturer and see what they say.

 

[DVCNick]

Hmmm... ok will do, thanks.

 

[mabrungard]

While you can create a good storage solution by starting with 4 buffer, you definitely shouldn’t use it as-is for probe storage. It doesn’t have a high enough ionic strength and it will leach the electrolyte out of the probe.

 

[DVCNick]

My probe storage solution is here now too... should have everything.

I called Milwaukee to ask about the liquid level in the probe (it has since dropped further) and they indicated that it is temporary storage solution designed for shipping/transport, and what I'm seeing is normal.

My next mash will be properly pH measured!

 

[balrog]

Hate to pick a nit here, but I always say my next <fill in measurable event name here> will be properly measured.
Just, measured.
I mean, I *try* to make sure I do it properly, uncontaminated, properly calibrated, careful procedure, properly recorded, but I know for a *FACT* that I have screwed up any number of those things at different times.
Practice makes perfect.
You certainly have a nice tool to use.