Electronic ph meter

[Eric]

How accurate need we be Dunc? Better than a point or two?

As as been observed elsewhere, I'm a bit OCD when it come to numbers... But the inaccuracy I noticed in my pH strips was certainly of the order of several points. I just can't remember exactly how many. Could even be up to +/- 0.5.

Thanks for this Dunc, a lot more than I've experienced, which is generally as subjective to colour interpretation as any difference to my predicted value in an all pale malt mash. As said, I have no meter in use to make comparison. Maybe down to the type of stip?

But why calibrate at pH 7 when brewing starts with a mash that is roughly fifty times more acidic than that level?

Because 7.01 and 4.01 are the standard calibration points for all pH meters. Those are the calibration buffers you can buy most easily, and they're the values the meter is expecting when you put it into calibration mode.

Right, I recalled reading of others with intermediate values. I noticed that temperature correction on these lower pH buffer solutions was of lesser significance over the temperature and pH range of brewing.

Greenxpaddy, sorry for taking this off target, your objective was towards the other end of the pH scale, but I've got a bee under my bonnet as to why brewers struggle with a subject that started in a brewery over a hundred years since.

[gregorach]

How accurate need we be Dunc? Better than a point or two?

As as been observed elsewhere, I'm a bit OCD when it come to numbers... But the inaccuracy I noticed in my pH strips was certainly of the order of several points. I just can't remember exactly how many. Could even be up to +/- 0.5.

Thanks for this Dunc, a lot more than I've experienced, which is generally as subjective to colour interpretation as any difference to my predicted value in an all pale malt mash. As said, I have no meter in use to make comparison. Maybe down to the type of stip?

Like I say, don't take the precise number too seriously... But certainly a larger error than I'm happy living with when it comes to mash pH. I've tried a couple of different types of strip and not found one significantly better than the other.

[greenxpaddy]

Here's how inaccurate they are. I was getting a ph of 5.0 or less with strips. An accurate reading from calibrated ph meter is 5.6 for the same brew.

[BlackRocksBrewery]

I would love to have some feedback on the Voltcraft pH meter (see 2nd post on this thread) as this is half the price of my Hanna HI 98128.
I am very impressed with the customer service of Hanna but I only experienced this after having bought a faulty instrument from RS. The original unit was slow to calibrate and was inconsistent when taking readings. Hanna supplied a new unit and I have only used it for a few days but so far it is looking good.
I think the approx £100 that I paid was very expensive for something to check my mash pH. However many suppliers of pH papers dont work with my water so I have to use a meter.
(Greenxpaddy - I sympathise. I used to use pH papers - successfully - but there is some change in the Severn Trent water over 2 years ago in my very local area -Cromford, South Derbyshire - that prevents their use.

[orlando]

I would love to have some feedback on the Voltcraft pH meter (see 2nd post on this thread) as this is half the price of my Hanna HI 98128.
I am very impressed with the customer service of Hanna but I only experienced this after having bought a faulty instrument from RS. The original unit was slow to calibrate and was inconsistent when taking readings. Hanna supplied a new unit and I have only used it for a few days but so far it is looking good.
I think the approx £100 that I paid was very expensive for something to check my mash pH. However many suppliers of pH papers dont work with my water so I have to use a meter.
(Greenxpaddy - I sympathise. I used to use pH papers - successfully - but there is some change in the Severn Trent water over 2 years ago in my very local area -Cromford, South Derbyshire - that prevents their use.

I have one which I purchased recently. So far have only calibrated it (brew day today so will be used in earnest) but the impression is extremely positive. This is a well built piece of kit. I like the separate probe which is designed to be held in its own pot of fluid to protect it. It has a large display on a chunky body that has a stand built into the back of it. Calibration is simplicity itself with 2 tiny screws under a flap on the right hand side. I noticed that during calibration the numbers fluctuated for awhile but this happens with most meters I understand and they do say up to 5 minutes before the reading is steady. If anything untowards happens with it I will post again but suspect it is a winner. I had one of the Hanna ones that were old stock from years back and quite frankly it showed, it was clunky and a nightmare to calibrate. Hanna service was very good and they took it back and calibrated it for me but it now lies abandoned as it just keeps giving an error reading when I use it.

[Dave S]

+1 on the voltcraft. I got one at Christmas and I've used it for, I think 3 brews with no problems so far.

[orlando]

Well having used it for the first time today it was a pleasure to use it. Very easy big numbers so easy to read used it to measure mash pH and final runnings pH and a beer coming to the end of fermentation to check its pH too.

[BlackRocksBrewery]

I have a real problem in that pH papers DO NOT WORK. I am in a very small area of Severn Trent where the readings do not tally with the papers. A mile away and things are totally different in that everything is as expected. Papers show very low pH readings. This is a real concern to me. I have tried many different makes. Problem is that they did once show a realistic reading when I lived 100m away.
I got a HI 98128 from RS and it was no good. When I contacted Hanna they were excellent. I can fully recommend them.
Now using the meter and very happy with it. My only concern is the life of the unit.