Holy Crap my new pH meter seems high maintenace!

[FirstAidBrewing]

Hey all,

So no pun intended, I am diving into the world of water chemistry and just picked up the following pH meter from my LHBS:

http://www.milwaukeetesters.com/pH55.html

While I am excited to figure out where I can improve my water, I'm reading the instructions on this device and... holy crap! The calibration isn't too difficult; my question is more related to the maintenance.

If I am reading the instructions properly, it looks like I have to keep this thing constantly soaked in bottled water or the calibration solution that it came with (per the instructions: 'Do not store the unit in the protective cap.' I found that funny).

I guess I didn't imagine having a cup of bottled water for my meter to soak in being a constant part of my brew setup. I keep saying bottled as that word was repeated constantly in the instructions.

Thoughts? And is this thing really worth what I paid for is as opposed to some pH test strips?

Thanks!

 

[LandoLincoln]

They sell storage solutions for pH meters. I'd get some of that stuff.

My Hach Pocket Pro+ requires no storage solution. Which is very nice.

The PH55 is only accurate to a tenth of a degree. Not very precise for our needs. Good luck with it.

 

[FirstAidBrewing]

And you store your meter in a cup of that solution? I know that's what the instructions say to do and I will comply, but just seems an odd thought to me to just have this thing sitting in a cup 99% of the time.

 

[ajdelange]

And is this thing really worth what I paid for is as opposed to some pH test strips?

Test strips are usually in error by up to 0.3 pH. The advertized accuracy here is 0.1 pH. That's 3 times better but about 5 times worse than you really want for brewing so I think the answer to your question is 'marginally'. I really wish home brew shops wouldn't sell these ineffective meters. For around $100 you can get a pretty good meter. So you saved $40 and have a pretty nice paper weight. Well, I exaggerate a bit. It is better than strips.

pH meters are tremendously advanced relative to what they were only a few years ago but they still require calibration before each use and typically storage in a special storage solution. Most designs are such that the storage solution is held in a 'soaker bottle' which attaches to the electrode or in some sort of electrode cap.

 

[FirstAidBrewing]

Interesting... maybe I'll be returning this thing. Any suggestions on a replacement?

 

[biertourist]

They ARE very high maintenance devices; unfortunately you learned that after purchasing rather than before.

I don't know anything about the Milwaukee ph 55, but I have the MW102 (0.01 accuracy and resolution) and you can just store the electrode in the storage solution- fill the cap 90% full and then slide it on.

You will also need 2 calibration solutions -and they go bad after about a year. Eventually the electrode will get fouled and it will start taking longer and longer to calibrate and to reach equilibrium; then you need to buy electrode cleaner.

After a few years you'll need to replace the probe which will cost as much as a new meter.



They ARE high maintenance devices. I'd love to see one that rapidly calculated with a 0.01pH accuracy and resolution and with a single button push calibration procedure for under $100 -that would make me buy a new one.

Once you get familar with your typical mash pH's for different colored beers with your water, you need them less and less; brew a really strong beer? -Pull it out again. After a while you really know what your pH is going to end up unless you have huge seasonal swings in your water (luckily I live in Seattle and we have quite consistently low mineral content water throughout the year). -Play with sour beers? pH meter gets useful again.

Going to make a wine or mead? -Again, pH meter becomes useful again.



I would consider it a year's worth of "education cost", personally. Expect that one year to cost you $200-$250.


Adam

 

[biertourist]

They sell storage solutions for pH meters. I'd get some of that stuff.

My Hach Pocket Pro+ requires no storage solution. Which is very nice.

The PH55 is only accurate to a tenth of a degree. Not very precise for our needs. Good luck with it.

Hmm... Torn on the Hach Pocket Pro+.

Love the accuracy.
Curious about how much 3 point calibration gets you vs. 2.
The meter costs $115, with replacement sensors for $70.29.


-How fast is the calibration? How long does it typically take to stabilize?


I like that the Milwaukee has 0.01+/- accuracy and resolution and that it uses industry standard replacement probes, so I could replace it with an even more accurate probe, but I HATE the calibration procedure and how long it takes.

If the Hach doesn't require storage solution AND it calibrates faster, I'd say that's a pretty great combination of features.


Adam

 

[wardens355]

I don't know anything about the Milwaukee ph 55, but I have the MW102 (0.01 accuracy and resolution) and you can just store the electrode in the storage solution- fill the cap 90% full and then slide it on.

I have one as well. It has worked well for me over the last 6 months, so I would recommend it. Around $110 on Amazon. Minor point, the accuracy is +/- 0.02, resolution 0.01. Looks like Milwaukee has a typo on their webpage.

 

[LandoLincoln]

Hmm... Torn on the Hach Pocket Pro+.

Love the accuracy.
Curious about how much 3 point calibration gets you vs. 2.
The meter costs $115, with replacement sensors for $70.29.


-How fast is the calibration? How long does it typically take to stabilize?


I like that the Milwaukee has 0.01+/- accuracy and resolution and that it uses industry standard replacement probes, so I could replace it with an even more accurate probe, but I HATE the calibration procedure and how long it takes.

If the Hach doesn't require storage solution AND it calibrates faster, I'd say that's a pretty great combination of features.


Adam

Calibration doesn't take that long on the Hach.

1) Turn the meter on.
2) Remove cap from sensor.
3) Push a button to go into calibration mode.
4) Rinse the sensor with DI water and blot dry.
5) Pour calibration solution #1 into the cap.
6) Put it on the meter.
7) Wait for meter to stabilize then push the calibration button to save. I haven't calibrated it that many times, but I think that the stabilization only takes about 90 seconds, tops.
8) If you want to do a second (or third) calibration solution, then do steps 4-7 again with the second solution.
9) Push and hold the calibration button to end the calibration until it shows "END" on the display.
10) Rinse once again with DI and blot dry.

The plus version of the meter allows one to use calibration solutions other than 4/7/10 if you'd like.

 

[FirstAidBrewing]

Okay, semi-related question then: I just ordered a water report from a lab. I have public water so I don't expect it to change that much over the course of a year. aside from acid malt, how much will different malt roasts affect pH? I figure I can use this thing a few times before it dies on me to figure out what the pH change will be from water to mash, assuming that different malts have an estimatable effect on pH

 

[ajdelange]

Curious about how much 3 point calibration gets you vs. 2.

Measuring mash: absolutely nothing
Measuring anything else: absolutely nothing except the convenience of not having to stop and do another 2 point cal if switching over from measurements at < pH 7 to measurements > pH 7.

-How fast is the calibration? How long does it typically take to stabilize?

It never stabilizes completely. However it settles to with about 0.01 pH of what appears is going to be the equilibrium value within a couple of minutes. Part of the art is to wait long enough that 99.9% of the drift is over before accepting the cal. The fact that this meter allows you to do that is one of its bit pluses. The fact that the Hanna pHEP meters don't removes them from consideration.

Note: as the electrode ages it takes longer and longer for equilibrium to be reached.

I like that the Milwaukee has 0.01+/- accuracy and resolution and that it uses industry standard replacement probes, so I could replace it with an even more accurate probe,

No such animal. With an electrode 'accurate' to 0.01 (which really means stable to 0.01 over a reasonable length of time because you have to calibrate it before each use) accuracy is determined by the buffers.

..but I HATE the calibration procedure and how long it takes.

How much time do you waste, for example, sleeping?

If the Hach doesn't require storage solution AND it calibrates faster, I'd say that's a pretty great combination of features.

They are both good meters (especially for the money). I don't think you can count on the Hach being much faster. Hach brags about the quick response of its electrodes but all the other manufacturers do too.

 

[darylwoodman]

Okay, semi-related question then: I just ordered a water report from a lab. I have public water so I don't expect it to change that much over the course of a year. aside from acid malt, how much will different malt roasts affect pH? I figure I can use this thing a few times before it dies on me to figure out what the pH change will be from water to mash, assuming that different malts have an estimatable effect on pH

Watch out...and don't assume it won't change over the course of the year. I get my annual water report for Cary, NC, and I took the time to speak with the chemist at the public works department, and here is why.

Our town uses Chloramine in Jan-Feb and April-Dec. In March they flush their water system with Chlorine. It doesn't hurt to call and speak with someone. I think our local chemist was actually happy to speak about what she does and how it affects the homeowner. We don't all just accept that water coming out of the tap is a constant.

Cheers-

 

[Hello]

Watch out...and don't assume it won't change over the course of the year. I get my annual water report for Cary, NC, and I took the time to speak with the chemist at the public works department, and here is why.

Our town uses Chloramine in Jan-Feb and April-Dec. In March they flush their water system with Chlorine. It doesn't hurt to call and speak with someone. I think our local chemist was actually happy to speak about what she does and how it affects the homeowner. We don't all just accept that water coming out of the tap is a constant.

Cheers-

Last one they sent me was 2014. Do you get more frequent updates?

 

[ajdelange]

.... aside from acid malt, how much will different malt roasts affect pH?

That depends on the water and the malts, including the base malt. If the water isn't very alkaline and the base malt has low buffering capacity a colored malt can pull the pH quite a bit. If, OTOH, the base malt has high buffering capacity and the water is alkaline then a colored malt won't pull pH much at all. That's why we are always looking for ways to get rid of the water's alkalinity.

 

[darylwoodman]

Last one they sent me was 2014. Do you get more frequent updates?

You know, my last may have been 2013. I'll have to check. Time flies by so quickly. If you have 2014 in pdf, would you mind sending me a copy?

Cheers,

[email protected]

 

[Hello]

You know, my last may have been 2013. I'll have to check. Time flies by so quickly. If you have 2014 in pdf, would you mind sending me a copy?

Cheers,

[email protected]

Actually, I have 2013, which was sent to me in 2014. They're literally a year behind. In fact, they sent it on June 4th because they had just finalized it. If you go to their page, they only have 2012 and 2013 listed.

I'm sending a sample of my water source into Ward Labs once the temp hits above freezing. I have a drinking water hose and an inline filter that I will begin using early March.

 

[darylwoodman]

Actually, I have 2013, which was sent to me in 2014. They're literally a year behind. In fact, they sent it on June 4th because they had just finalized it. If you go to their page, they only have 2012 and 2013 listed.

I'm sending a sample of my water source into Ward Labs once the temp hits above freezing. I have a drinking water hose and an inline filter that I will begin using early March.

At this point I'm solely using Campden tablets--1/2 for 5 gallons. My last five or so kegs have been so good, I'm scared to change. I thought about getting a chloramine filter on an inline hose fitting--an RV one, perhaps what you have. The thing is, I will probably still use the Campden tablet though. I hate the idea of wasting so much time and effort on a whole brew batch and not throwing is something as cheap as a tablet.

 

[orangehero]

Once you get familar with your typical mash pH's for different colored beers with your water, you need them less and less; brew a really strong beer? -Pull it out again. After a while you really know what your pH is going to end up unless you have huge seasonal swings in your water (luckily I live in Seattle and we have quite consistently low mineral content water throughout the year). -Play with sour beers? pH meter gets useful again.

Going to make a wine or mead? -Again, pH meter becomes useful again.

I would consider it a year's worth of "education cost", personally. Expect that one year to cost you $200-$250.

And if you get a new batch of base malt.

 

[ajdelange]

And if you get a new batch of base malt.

In #22 of https://www.homebrewtalk.com/f128/new-building-water-profiles-what-did-i-do-wrong-516415/index3.html I show what can be expected to happen with 80% base malt with DI pH 5.68 ±0.05 and buffering -46.6 ± 5 mEq/Kg-pH with 20% colored malts with various random properties typical of such malts with standard deviation in DI pH of 0.1 and standard deviation in buffering of 10 mEq/kg-pH in a DI water mash. Don't go there. The picture is here. But first, if we think a malt has DI mash pH of 5.68 because people have measured it there but are uncertain because we have a different bag of malt or even a similar malt from a different maltster we are uncertain. Based on the normal distribution of uncertainty we might expect 100000 mashes made with Malt X to be distributed something like what is in the first histogram below. The most common peak is at 5.68 because that's what we have decided the average is for this malt but note that there could be mashes at 5.58 or 5.78. If the malt in question is Maris Otter we have, in fact we have measured it as high as 5.78.

If we now add 20% colored malts with average properties as given above the picture shifts to that of the second and third histograms below (the differences between them will be discussed in a moment. The average mash pH drops to about 5.55 and while there is a spread it appears that most mash pH's would fall between 5.48 and 5.64. The difference between the second and third pictures is that in the second we have removed the uncertainty in the properties of the base malt, that is, we assume you have measured it. The uncertainties of the colored malts (there are 4 in this 'experiment') clearly overwhelms the uncertainties in the base malt BUT that assumes that the uncertainty in the base malt buffering is pretty small to begin with. We modeled 5 mEq/kg around a mean of -46.6 mEq/kg-pH (about 10%). If we assumed a mean of -20 then the colored malts we added would result in a displacement to lower pH of about double what the pictures show.

I know this is probably getting too complicated but the main message is that one ought to be able to get a pretty good mash pH prediction if he knows the properties of the base malt and uses average properties of colored malts. I'm suggesting that one measure the properties of the base malts he uses. The first measurement is a DI mash pH. The second is a measurement with DI water and about 25 mEq of acid per kg malt. So for example if one mashed 40 grams (1/25 th kg) of malt with 100 mL of water (that's what I do when I measure malts) he'd add 1 mEq of acid which would be 10 mL of 0.1 N sulfuric acid (sold by Hach and others for alkalinity testing).
If this results in a pH displacement of 0.5 then the average buffering capacity of this malt in the region of most interest (near mash pH) is -25/0.5 = -50 mEq/kg-pH. Knowing that much about the base malt it's easy to calculate the effects of alkalinity, acid addition and colored malts to acidities are approximately known and to do it fairly accurately as the colored malts are in relatively small proportion.