Help - "5.2" works for me; I know it shouldn't, but it does! I think.

[bob1852]

Tap water report from Ward's:

Grist
10 lbs 2-row
1 lb Munich
0.75 lb 60L
0.5 lb flaked barely

1.3 qt/lb mash ratio
Mash temp 153*F for 60 minutes

post-mash pH without "5.2" = 5.45 (taken by putting probe into mash)
post-mash pH with "5.2" = 5.18 (taken by putting probe into vessel collecting sparge water)

mid-sparge pH without "5.2" = 5.82 (taken by putting probe into mash)
mid-sparge pH with "5.2" = 5.29 (taken by putting probe into vessel collecting sparge water)

pH meter: http://www.marinedepot.com/ps_viewi...tm_campaign=adwordsfroogle&utm_content=HN1151

pH meter testing (room temp, 7.0 solution)

pH meter testing (room temp, 4.0 solution)

pH meter testing (~167*F, 4.0 solution)

pH meter testing (~164*F, 7.0 solution)

pH meter testing (~54*F, 4.0 solution)

pH meter testing (~50*F, 7.0 solution)

 

[ajdelange]

I can't fathom what you are doing here other than exposing an instrument designed for a maximum temperature of 50 °C to a temp 23 °C higher than that. You may well have damaged the electrode but then again perhaps you didn't.

I understand what you mean when you say you put the electrode into the mash (which you shouldn't do but rather place it in a cooled sample of the liquid from the mash) but I don't understand what you mean by putting it in the vessel collecting the sparge water. Does this mean the water to be used for sparging or does it mean the runoff. The pH of the mash and the runoff should be the same. Runoff should, of course, also be cooled before measurement. Where is the 5.2? How is the mash without and the runoff with?

Having exposed the meter to the high temperatures I would immediately try to recalibrate it with fresh buffers at room temperature and then do the stability checks suggested in the Sticky on pH calibration. You may have gotten away with it but even if you didn't damage anything this time your electrode will last a lot longer if you measure cooled samples. Besides that all references to pH here and in the modern literature (sometimes in the older books it is uncertain) are to pH measured at room temp.

 

[bob1852]

I've used this meter for many different things over many years yet it always measures true when I check calibrations.

I'll continue to take more measurements and pictures during future brew days. My mid sparge pH readings are taken by puting the unit into the bucket that is collecting the sparge runoff.

Thanks for replying to my thread AJ. It's a fascinating subject for me, even moreso because my results are not the norm.

 

[MNDan]

I got a laugh out of seeing that pH meter in 167F liquid. Hopefully providing me that didn't cost you a pH meter.

 

[afr0byte]

I've used this meter for many different things over many years yet it always measures true when I check calibrations.

I'll continue to take more measurements and pictures during future brew days. My mid sparge pH readings are taken by puting the unit into the bucket that is collecting the sparge runoff.

Thanks for replying to my thread AJ. It's a fascinating subject for me, even moreso because my results are not the norm.

How can you be sure your meter is accurate, though? The meter isn't rated for taking measurements at the temperatures you were using.

EDIT: Also, why are you measuring the buffers at 10C?

 

[bob1852]

I got a laugh out of seeing that pH meter in 167F liquid. Hopefully providing me that didn't cost you a pH meter.

Tt's been working fine for many years. Just used it to check some Star San pH last night. Right where it should be.

How can you be sure your meter is accurate, though? The meter isn't rated for taking measurements at the temperatures you were using.

EDIT: Also, why are you measuring the buffers at 10C?

The buffer solutions have temp corrections on them for temps up to 50*C and it reads within the margin of error for the range of those temps (10, ~20, 50+)

I'll just go back into my hole now, since what I'm doing shouldn't be working.

 

[afr0byte]

Tt's been working fine for many years. Just used it to check some Star San pH last night. Right where it should be.



The buffer solutions have temp corrections on them for temps up to 50*C and it reads within the margin of error for the range of those temps (10, ~20, 50+)

I'll just go back into my hole now, since what I'm doing shouldn't be working.

Well, the point I was trying to make is can you really be sure it was "working" since your meter isn't rated for the high temperatures?

 

[bob1852]

Well, the point I was trying to make is can you really be sure it was "working" since your meter isn't rated for the high temperatures?

I talked with the tech dude at Hanna, and it's pH ATC rated to at least 120*F (they won't make any claim above that, and while they say it would probaly be accurate at mash temps of ~152, he believe it'll burn through electrodes pretty quick - yet I've used it for years).