pH meter calibration

[JimmyT]

How often are you supposed to do the calibration on a pH meter? So far I've done it before I used it on each new batch I started. I'm just wondering if that's necessary or not.

 

[Norske]

I calibrate each time before use.

 

[Boatboy24]

Same here, before each use. I've read you should do it once a month (don't recall where), but I don't use mine nearly that often.

 

[Paulietivo]

What ph meter are you guys using? Im looking for an economical way to test the ph of red wine after fermentation. The ph test strips are useless as the red wine stains them and renders them unreadable. Ive found several ph meters on several sites ranging from $20 to $300 but most all have some horrible reviews. And Im trying to keep the cost around $50, does anyone have any info?
Hanna Instruments HI 98103B
Dr. Meter® PH100 0.01 Resolution High Accuracy Pocket Size pH Meter
Milwaukee pH55 pH/Temp Meter

Thanks
Paul

 

[wineforfun]

Per JimmyT's recommendation, I bought a Milwaukee pH56.
Here is a link to where I bought from.
http://www.testequipmentdepot.com/milwaukee/ph-meters/ph56.htm

 

[stickman]

As the others have pointed out, calibration should be done at each use. Of the three units you list, in my opinion, only the DR Meter has the accuracy needed for wine, double junction electrode .01 accuracy, it looks a lot like the Extech models. I've only had one meter, the Oakton 30, and it has worked well for over 5 years, the electrode life is between 6 months to 1 year depending on storage conditions, and you'll find that is the main issue with PH meters in general. Overall you have to consider the accuracy, electrode life and the cost of the replacement. I'm sure others can comment on the units they have used.

 

[Jimyson]

I'm not really happy with my pH56. Getting into calibration can be a little hassle sometimes as the button on the thing requires you to push really hard and in the correct spot. This is likely because it's a handheld splash proof unit. I think if I had the choice again, I would get a portable one that has an external probe.

And, as others said, I calibrate at each use with pH4 and 7. You can get this on Amazon for pretty cheap.

 

[Paulietivo]

As the others have pointed out, calibration should be done at each use. Of the three units you list, in my opinion, only the DR Meter has the accuracy needed for wine, double junction electrode .01 accuracy, it looks a lot like the Extech models. I've only had one meter, the Oakton 30, and it has worked well for over 5 years, the electrode life is between 6 months to 1 year depending on storage conditions, and you'll find that is the main issue with PH meters in general. Overall you have to consider the accuracy, electrode life and the cost of the replacement. I'm sure others can comment on the units they have used.

Thanks guys for the info.

Stickman, the Dr Meter was my first choice but was skeptical because its sold on amazon & is the newer upgraded model to a cheaper $20 version. Whats interesting is that it uses 4.0 & 6.86 & 9.18 calibration solution, not 7.01. I asked amazon why & received this response from someone named Randy.
"It's more precise than other meters, for wine as long as the wine is in the perimeter of the meters highs n low."
Ive just never saw this meter being talked about for winemaking but I think I might go for it.
How do I test for TA using the meter? Is there a solution for that?

Paul

 

[sour_grapes]

Whats interesting is that it uses 4.0 & 6.86 & 9.18 calibration solution, not 7.01. I asked amazon why & received this response from someone named Randy.
"It's more precise than other meters, for wine as long as the wine is in the perimeter of the meters highs n low."

It is bordering on ridiculous to cite a pH to 2 decimal places when it is to be made by mixing a powder with "250 ml" water. They must expect that you are able to be damned precise in measuring your 250 ml of water if they think you can nail the pH to 0.01.

How do I test for TA using the meter? Is there a solution for that?

See this post and the others just above it and following: http://www.winemakingtalk.com/forum/showpost.php?p=560270&postcount=9

 

[Paulietivo]

Sour, thanks. I did read that it had to go to 8.2 to test for ta, but I wasn't sure what was being added to the sample. I'd rather just purchase that instead of the acid test kit.
And yea all the ph meters ive looked at had issues with calibration, storage and replacing the probe. And in all the videos ive looked at there was no precise calibration and or ph reading of wine that we could say is 100% accurate.
I want to test the ph of my red wine because I suspect it has a high ph. In the past Id prob just drink it but I want to try and adjust the acid to age longer.

 

[sour_grapes]

By the way, my comments were not meant to imply any criticism of what you are doing or of the instrument you bought. I just found the gentleman's comments about precision, and the figure given to two decimals place, quite risible.

The test kit would not be a bad investment. It is all of $12 from MoreWine:http://morewinemaking.com/products/emmorewineem-acid-test-kit.html

Here are the instructions:
http://morewinemaking.com/images/file.php?file_id=1343

 

[stickman]

The 2 decimal reference on the buffer is just what the manufacturer says it should be based on the formulation, but as sour indicated it is comical, most people will have to assume it is close enough for their purposes. Some manufacturers indicate that based on the buffer formulation up to a 2% error in dilution water is acceptable, and the final buffer PH will have an accuracy of plus or minus .02 to .04 depending on PH, this assumes you are using good distilled water without co2 contamination etc. Anyone who has used a PH meter knows just how finicky and sensitive these things are, about all you can do is get the best meter your pocket book will allow and calibrate at each use. The nuances of PH measurement techniques, equipment, and standards, are as vast as the nuances of winemaking, but I'd rather be making wine.

 

[Paulietivo]

Thanks, I had no idea that the .02 decimal places were until I looked back at the product to see the calibration solution was indeed powder & neasuring the water exactly wouldnt really be possible. That being said i have not ordered one yet.
After further reading, since wine is between 3 & 4 on the ph scale & calibration is beteen 4 & 7, where do i get calibration solution at or below 3? The only ones I found went from 4-10.
The ph meters are becomming a (P)ain in the (H)orses *** & I dont even have one yet....
Next time I buy from papagni vineyards I adjust the ph before fermentation. Yes I didnt do that cause I assumed it was already adjusted & didnt have to with kits & other fresh juices. Their website clearly stated to adjust the ph to 3.3 or 3.4 or blend with high acid must before fermentation. I did blend 12 gallons of zinfandel with 6 gallons of barbera but this batch has been a pain. I think theres a serious pectin haze becase its been 6 months & it looks very cloudy after 3 racking & kielosol chitosan.
Ive just now starting to get the importance of the chemistry in my winemaking. Better late then never, I suppose

 

[stickman]

There's no reason to get overly concerned, you do the best you can with what you have. Most of us are lucky to have any kind of PH meter at all. Remember this is supposed to be fun.

PH 3 buffer is available, but most of the economical standard PH meters only recognize certain buffers, so during calibration you go with the manufacturer recommendation, typically USA (pH 4.01, pH 7.00 and pH 10.01) or NIST (pH 4.01, pH 6.86, and pH 9.18). There are more expensive meters with electrodes specifically designed for wine, as well as meters that will calibrate at other ranges including between 3 and 4 PH etc., but they are marketed to wineries and laboratories and are cost prohibitive for the average home winemaker.

 

[Paulietivo]

I ordered the Milwaukee pH 55. Not the best meter but better then the economy one. Its ok that the stress comes now over equipment and other issues for it will leave very quickly as I sip my wine. I figure to get some good use out of it this year, as I finish this batch, Ill have my chilean juice buckets ordered for may and california buckets in september. Also I can start checking my pool water and see how accurate it is.
Thanks for all your guys help and input. Ill keep you all posted.

Paul