pH Meters

[Gerry]

What are people using to measure their mash pH? I have looked at pH meters from Dick Smiths and various garden supply retailers, which offer a similar digital pH meter, which has a temp range of up to 50 degrees C. Has anyone tried these or is there a better option?
Cheers Gerry

[Richee]

Hi Gerry,

I've tried the pH strips but for me there are too many shades to match accurately,although you can buy the 'colourphast' variety that target specific pH ranges.

I bought a pH meter on trademe for about $100 from memory. Most important step is to calibrate them properly. Mine came with two calibration solutions that I have subsequently found were not accurate. Calibration solutions only have a certain shelf life once opened. I was reusing the solution as well which is a no no. I recently bought a pH meter cleaning kit and calibration solutions from this out fit:

http://www.evergreenhydro.co.nz/shop/Electronics/CalibrationCleanin...

Best thing I ever did. I calibrate that meter prior to each brew day. If possible get a meter that has two point calibration. Accuracy is excellent +-0.1

0-50C seems typical for automatic temperature compensation. Best bet is to cool each sample down to around 25C as the higher the temp the lower the pH.

For a really good summary have a look at the following link:
http://braukaiser.com/wiki/index.php?title=Understanding_Mash_pH

Let me know whaich way you go!

Regards
Richard.

[Gerry]

Hi Richard,
Thanks for the information. Yes, I gave up on pH paper for the same reason as you. The 25C reading makes sense and I'll purchase a digital meter before the next brew. Braukaiser is an interesting website.
Cheers
Gerry

[Haish]

You should measure pH at mash temperature because that is the actual pH the enzymes are experiencing. Measuring at 25 degrees introduces an error because the enzymes aren't working at that temperature. pH 5.3-5.8 would be the approximate range at 25 degrees for your mash pH to be in the right range.

Here's an article on pH meters and temperature compensation:
http://www.coleparmer.com/techinfo/techinfo.asp?ID=559&htmlfile...

[Richee]

Hi Haish,

Not that easy to measure at mash temp as the ATC of most pH meters is 0-50C, so you have to take a measure at the mash temp and then try to adjust it again after the pH meter has tried. Easier to cool the sample?? You are right with your specified pH range @ 25C, does it matter if the enzymes are not working at the cooler temp?

Rich

[denimglen]

Or you could just buy a tub of Five Stars pH 5.2 buffer ;-)

That's what I'm considering doing, that and a little gypsum to harden the water and I should be good to go.

[Richee]

Would be very interested in the results of the 5 star.
Rich

[Haish]

I don't think the ATC would be thrown out too much operating above 50 degrees. It would probably be more accurate than measuring at 25...

[Gerry]

I guess you could always calibrate the pH meter at mash temperature to get around the issues of measuring pH.

[Dale]

Hey guys

Does anyone know what a PH7 buffer solution is made of? I have gotten about 10ml into my mash and not sure if that really matters or if it is a poison. It was from the DSE PH Meter.

Thanks

[JoKing]

That's it - tip your mash down the sink. That shit is toxic.

Or its just water.

[James P]

All the pH buffer solutions online seem to contain toxic shit as Jo said.... I'd tip it.

[denimglen]

Tip it. To be safe.

It won't be just water as water doesn't have any buffering power.

It's maybe like 20 - 40 bucks worth of ingredients - spread out over all the good batches the cost of tipping this one equals bugger all.

I choose to dump a 4.5kg grain bill last week after I spilled it all over my garage floor. I considered using it but with all the bog dust, paint dust and metal filings I reckoned it was safer to take the loss and dump it.