Hanna Instruments (pH meters) sale

[evoo4u]

Being on their mailing list, I received an email today from Hanna Instruments which might be of interest to anyone looking at pH meters (or a stir plate):
https://blog.hannainst.com.au/2016/07/26/ph-blowout-sale/
Even if you're not a potential buyer, there are some good blogs on pH, electrodes, calibrating, etc on their site.

 

[MHB]

Sweet!
Mark

 

[Benn]

Recon this would do the job for brewing? I can't find any info on their website.

I'll go buy one tomorrow if it's suitable

 

[Benn]

Found this
"0-50deg temperature calibration," what's the go with that? Does that mean it'll be shithouse for measuring mash Ph or what?
Ahhhh fucken science, why can't it be straight forward.

 

[evoo4u]

"0-50deg temperature calibration," what's the go with that? Does that mean it'll be shithouse for measuring mash Ph or what?

I've got an awful feeling this reply might be duplicated, like the original one last night. Dunno WTF's going on with my pc/the forum software???

Anyway - I have the next model up, I think (the 98128) which also has those temp limits. But by the time I take a small sample from the mash tun and get the meter ready, the sample's cooled down to below 50C anyway, so it's not an issue. The 98128 also displays the temperature of the sample which is nice.

The resolution (and accuracy) of the 98108 is 0.1 which will get you where you need to be. The 98128 resolution is 0.01 (but accuracy is 0.05) which is better, but not really necessary for our purposes.

EDITS IN ITALICS - The 98128 features auto calibration (makes it quick and easy), but the 98108 has manual calibration, so could be more of a fiddle.

Even though I normally read product manuals (yeah - weird, I know), this 'cloth junction' is a newie to me. The 98128 has a replaceable electrode, which apparently also has this 'cloth junction' feature, so I'd better re-read the manual.

Bottom line? The 98108 will be better than using pH strips, but don't forget to factor in some calibration solutions (bottles or sachets) and storage solution.

 

[Lyrebird_Cycles]

IMO you will get better results with a pH meter at ~20 degrees anyway. The ATC only corrects for probe effects, it doesn't know that the mash pH itself changes with temperature. Also probe life is much better if the samples are cooled before measurement.

On the subject of probe life: an ancient trick for rejuvenating a bad probe is to soak it in fresh pineapple juice for a day or so. Works amazingly well. Apparently the combination of Papain and acid cleans the glass.

 

[Benn]

Thanks all, I'll pick one up today.

 

[technobabble66]

Resolution to 0.1 is barely sufficient for our needs. It means that pH5.4 could be 5.35 or 5.44. Add an accuracy of -/+0.1 to that mean that your nice pH5.4 could really be 5.25 or 5.54.
Not great for mash efficiency really!
Given almost everyone on here who's bought a pH meter has reported to have used it a few/dozen times, discovered Bru'n Water etc are highly accurate predictors of mash acidity, then packed away the meter never to be used again, I'd suggest you'd want better resolution & accuracy to make it worthwhile getting the meter. You might as well rely on the fairly accurate spreadsheets.

TLDR: get 0.01 resolution with at least +/-0.05 accuracy. Otherwise, just trust the Bru'n Water spreadsheet.

2c

 

[Lyrebird_Cycles]

Apparently the combination of Papain and acid cleans the glass.

Should have said bromelain. Papain comes from papaw.

 

[Benn]

I stopped by Hanna today, bought the Ph meter mentioned above and the required bottles of solution...
Add in a Full Pint order, several AHB member bargains, a few other odds & ends and I'm well & truly careening down the slippery slope this month. Anyway, it sounds like Hanna are developing a digital test kit thats tailored to brewing i.e similar to the overseas offerings.
Could be good.

 

[evoo4u]

As you've no doubt gathered, it's critically important between uses, to keep the electrode wet, ideally in storage solution, otherwise the 7pH calibration solution. Sure, the pH meters do the job, but there is maintenance required - they're not just a 'use once in a blue moon' jobbie...

 

[hannainst]

Thanks for the shout out Evoo - I hope you all have gotten a chance to take advantage of the sales. Re temperature discussion - as Lyrebird said, it is better to keep sample testing below 30 degrees, although it is not necessary. This is both for increased accuracy of results, and to help prolong the life of your probe. Seeing as how the probe is made of glass, it burns out over time and temperature only speeds up that process.

I'll be hosting a Science of Beer Webinar next week where we go over all the tips/tricks for accurate pH measurements as well as how to maintain them. Feel free to register here if you're interested!

https://attendee.gotowebinar.com/register/4306643386166152706