… Did you notice a big difference in what the strips were reading and what the meter measured? I ask because I used (and trusted) ColorpHast strips and got quite comfortable with them. I had heard some say that good strips were perfectly acceptable for measuring the pH of the mash but I also heard a number of people say that strips cannot be trusted. I just read Chapter 7 of the Water book where it says something to the effect of… pH test strips are for amateurs and if you want to make great beer, get a meter. I bought a meter earlier this year (Milwaukee PH55) and I thought it would send me to the insane asylum because it was very jumpy and couldn’t even seen to read the calibration solutions (4.0 and 7.0) so I put it on the shelf and went back to the strips. After reading that I got the meter out, calibrated it, decided I was going to trust it and made a Helles. I’m usually close to a good mash pH (according to the strips) but the meter read quite high and I had to add a bit more acid than usual, which may or may not be good. Anyone else with experience going from strips to a meter? I realize some of the strips out there are really crappy. Cheers.
What you read in a book is just someones opinion/findings. If it is a scientific writing the research results have no validity unless the same results can be duplicated by independent testings.
In short my answer is no-haven’t used strips then a meter for brewing. I use an identical hand-held meter for water samples in my work and have found that its often useful to calibrate, use, and then pop the meter back into one of the calibration standards to get a sense of accuracy. Sometimes it drifts a few tenths of a pH unit over time. Assuming the calibration standards are completely accurate, why not dip a strip in to see how they compare?
From Bru’n water. “Mash pH can be checked about 5 minutes after combining the water and grist. But for more accurate results, the mash pH should be checked at around 15 minutes after combining the water and grist. Note: pH strips reportedly indicate the mash pH is about 0.2 to 0.3 units lower than actual. A calibrated pH meter is the recommended measurement source.”
I use the colorPhast strips and have consistently ended up at 5.0 for 20+ batches when bru’n water predicts 5.2 So for my uses I consider them accurate
I have to question the reliability of the pH meter you are using. This is not the first time I’ve heard of problems with that meter. If I read you correctly, it wouldn’t calibrate very well? That is a huge red flag if that is the case.
Good strips like colorpHast seem to be consistent in their reading. Correcting for the offset in the reading is simple. The one thing you need to keep in mind is that they must be kept away from moist air and they have a short life. After a year or two, they lose accuracy. Old strips need to be tossed.
That has been my same experience. It has gotten to the point I won’t even measure mash pH if I’m doing a style similar to one I’ve done previously since Bru’n Water always gets me where I need to be.
Will say I’ve got the same meter as Ken and while it worked just fine for about 6 months it’ll no longer calibrate so I’m guessing I’d have to replace the electrodes to get it to work again. I’d sooner spend money on a better meter than fix that one but since I’m able to get my pH into an acceptable range with Bru’n Water and can roughly verify it with colorpHast strips I doubt I’ll ever bother.
I have a PH55 and have the same problems with the calibration. I sent it back to Milwaukee and they sent it back saying it tested good. They also said that after calibrating the 7.01 side to rinse quickly with the 4.01 solution then use fresh 4.01 solution. It helped but I still get errors.
Does anyone have a Milwaukee MW101 meter ? I like to know if they are easier and more stable to use.
On the meter… I had documentation and an online video I used to calibrate. In the vid, the guy goes through the process in about 10 seconds but on mine it went on for much longer and occasionally the screen showed “WRNG” (wrong?) when I placed the meter in the 4.01 solution. I shelved it for awhile and then came back to it in the past week or so and it has been better. It calibrates quicker and measures 4.0 and 7.0 solution correctly. I even took my tap water which has been at pH 6.6 for as long as I can remember (even local commercial brewers I know have told me that Lake Michigan water in the Chicago area is always 6.6) and the meter read it at 6.6 so I feel like I’m having more confidence in it. Btw… this was a brand new meter that I bought and calibrated with all new calibration solution. I know that doesn’t mean the meter can’t be bad.
On the strips… I have gone back and forth with this hoping I could use ColorpHast strips forever. But the matching of the colors is what many skeptics mention. The strips could be faded, the brewer’s vision could be in question, matching the color on the strip to the key on the box does seem hit-or-miss to me. Then there is the .3 correction factor. I typically shot for a reading on the strip of about 5.0 at mash temp which would translate to about 5.3. I was able to do that regularly but I have to say that I still have the occasional issue with pale beers coming out harsh (even with the water diluted with distilled and sulfates and bicarb lowered considerably) and one reason for harsh-tasting pale beers is a poor mash and/or preboil pH. The part in the Water book I’m referring to is on page 140 titled HOW TO BREW SERIOUSLY GOOD BEER: BUY A PH METER. I already had one so I figured I would give it one more chance.
I’ve owned a MW-101 meter for the past 3 years and am quite impressed with it. It has retained its calibration with virtually no adjustment. It may be off a hundredth or so, but that has been correctable with the adjustment pots.
An important note is that the probe is stored in a half-liter bottle of 1N KCl storage solution when its not in use. I’m pretty sure that is a big contributor to its stability. I cut out a tight-fitting hole in the cap of the bottle and suspend the probe through the cap. It works well.
Considering that the MW-101 is just slightly more than the cost of ‘cheap’ meters at $80, I can’t see a reason to consider those cheap meters.
A couple of keys to maintaining a pH meter.
-
Rinse thoroughly with water before and after reading any buffer or sample. DO NOT wipe the bulb off, you can carefully tamp it on a smooth cloth or just give it a little shake to knock the water out.
-
Store in storage buffer solution. The bulb is filled with this solution and if you don’t store it in this then you are changing the concentration of ions inside the bulb. If the thing is very slow to come to the right pH and/or is erratic, chances are the probe is bad.
[quote=“tom sawyer”]A couple of keys to maintaining a pH meter.
-
Rinse thoroughly with water before and after reading any buffer or sample. DO NOT wipe the bulb off, you can carefully tamp it on a smooth cloth or just give it a little shake to knock the water out.
-
Store in storage buffer solution. The bulb is filled with this solution and if you don’t store it in this then you are changing the concentration of ions inside the bulb. If the thing is very slow to come to the right pH and/or is erratic, chances are the probe is bad.[/quote]
Thank you for that. I have the storage solution and the 4.0 and 7.0 solutions and the meter has been in the storage solution. When I take the reading of a mash sample, I rinse the probe with tap water, shake it a little and then place it right back in the storage solution. I have to say that I personally dislike all of the care required for the meter. I assume there is no alternative (at least one that is affordable) but the solutions are expensive and all of the storage, calibration, etc. is why I hoped to stick with the strips and why I didn’t buy a meter years ago.
