What percentage of brewers are using their pH meters properly?

[Cavpilot2000]

PM me. I have some real estate investment opportunities I think you will be interested in. Note that I'd write this if you expressed trust in any other spreadsheet/calculator too (including mine).

I would agree with this sentiment IF I had not validated its accuracy with my water, ingredients, and process.
Why on God's green earth would you NOT trust such a spreadsheet when you have validated its predictable accuracy over a period of time?
(Full disclosure: BNW typically predicts about 0.05 pH higher than I actually get, so I factor that in and it has proven to be absolutely predictable).

So by your logic, no matter how often a tool (which BNW is) is validated as accurate, you don't trust it? So you don't trust your pH meter either then, right?

 

[bracconiere]

I would agree with this sentiment IF I had not validated its accuracy with my water, ingredients, and process.
Why on God's green earth would you NOT trust such a spreadsheet when you have validated its predictable accuracy over a period of time?
(Full disclosure: BNW typically predicts about 0.5 pH higher than I actually get, so I factor that in and it has proven to be absolutely predictable).

So by your logic, no matter how often a tool (which BNW is) is validated as accurate, you don't trust it? So you don't trust your pH meter either then, right?

THANKS! i was worried the next post would be cussing ME out...lol

 

[Iseneye]

THANKS! i was worried the next post would be cussing ME out...lol

Huh. First time I've had to look for an ignore button on this forum. Found it.

 

[bracconiere]

Huh. First time I've had to look for an ignore button on this forum. Found it.

damn it, but i'm bored and lonely and brew beer! lol

 

[RevKev]

I can only speak for myself. Seeing people from industry, who either sell or use instruments and only follow SOPs. They can't even explain simple concepts or background. Makes me question every single person ever, life of an analytical chemist.

I am inclined to believe that homebrewers have the same knowledge base of people who use these instruments professionally.

 

[JimRausch]

What percentage of brewers are using their pH meters properly such that they gather accurate data from a well calibrated instrument?

An asinine and rhetorical question but one that needs to be addressed. Foregoing the crowd that "trusts" their water calculator and doesn't measure anymore.

Define 'proper usage'. I follow the directions that came with mine, calibrate it each time before using, take readings at about 10 minutes into the mash, and make sure it's at the proper temperature for the instrument. So far, in maybe 20 mashes since I got it, the reading has always been within 0.1 of what Brunwater has predicted. That makes me feel that I'm using it properly.

 

[ajdelange]

Why on God's green earth would you NOT trust such a spreadsheet when you have validated its predictable accuracy over a period of time?

Given what I know about how what determines mash and what I am able to deduce about how these predictors work, the problems inherent in modeling malts and, especially in the case of Brun water the recent reports of what is clearly a major flaw in its algorithm I would, if I found its answers in close agreement with my readings, question my readings.

(Full disclosure: BNW typically predicts about 0.5 pH higher than I actually get, so I factor that in and it has proven to be absolutely predictable).

So by your logic, no matter how often a tool (which BNW is) is validated as accurate you don't trust it?

Problem is that an instrument that has a bias error of 50 times it's precision is hardly validated as accurate. It is demonstrably inaccurate. Let me mention at this point that a large part of my professional background is in measurement so my perspective is doubtless a bit different than that of many of the readers here (you may be a history of art major for all I know). But if I paid a company good money to deliver an instrument that was supposed to measure quatloos to a precision of 0.01 and it came back with readings off by 0.5 Q (even consistently) I would not say "That's OK" and just add the 0.5 Q to each reading. I would be on the phone with the rep within the hour. If I added more pre-Quatloos and the Quatloo reading went down, I'd call the rep. If he didn't apologize and offer to send me a chip with new firmware on it that fixed both the bias and the other error I'd send the instrument back.

So you don't trust your pH meter either then, right?

Correct. No sensible person would. The responses of pH electrodes are known to vary over both the short and the long term. That is why we calibrate them before each use AND check on that calibration frequently during use AND run a stability test from time to time. When the offset gets to be above 20 mV and the slope less than 90% we don't just subtract 20 mV, multiply by 1.111 and sail on (though we can do this in a pinch). We recognize that our electrode is defective (at the end of its useful life) and replace it.

Do you know what confirmation bias is? I won't get into that here but if the term is unfamiliar to you look it up.

 

[ajdelange]

Define 'proper usage'.

Covered that in No. 3. Here's the link


https://www.homebrewtalk.com/forum/threads/ph-meter-calibration.302256/

 

[ajdelange]

I can only speak for myself. Seeing people from industry, who either sell or use instruments and only follow SOPs. They can't even explain simple concepts or background. Makes me question every single person ever, life of an analytical chemist.

I'm the same. My wife has spent lots of time kicking me under the table. In society today if someone says something stupid you are not supposed to question him. But as a scientist in a scientific setting you are.

I am inclined to believe that homebrewers have the same knowledge base of people who use these instruments professionally.

I have been asked incredibly naive questions by "professionals" more than once but I wouldn't give credit to the average home brewer for having their level of knowledge. Many of these guys are unpacking a new Hach or Milwaukee meter and these will be the first pH meters they have ever touched.

 

[ajdelange]

(Full disclosure: BNW typically predicts about 0.5 pH higher than I actually get, so I factor that in and it has proven to be absolutely predictable).

I did have a question I wanted to ask about this earlier but forgot. If indeed BNW is accurate except for the bias of 0.5 pH why doesn't its author simply subtract this bias off?

 

[RevKev]

I'm the same. My wife has spent lots of time kicking me under the table. In society today if someone says something stupid you are not supposed to question him. But as a scientist in a scientific setting you are.

I have been asked incredibly naive questions by "professionals" more than once but I wouldn't give credit to the average home brewer for having their level of knowledge. Many of these guys are unpacking a new Hach or Milwaukee meter and these will be the first pH meters they have ever touched.

Oh absolutely, people never learn unless corrected. Many stories for another day lol.

And you're right the average HBer likely is more inexperienced, they didn't likely learn it a long time ago and simply forgot it, they were never taught to start with. I'll give a HBer credit in application though, first time with the proper SOP a lot of people can get results. If they can interpret and understand why they got what they got, that's another issue, but industry unfortunately is the same.

 

[Cavpilot2000]

I did have a question I wanted to ask about this earlier but forgot. If indeed BNW is accurate except for the bias of 0.5 pH why doesn't its author simply subtract this bias off?

Let me preface by saying I misspoke with my decimal point. I find BNW to be off by 0.05 pH with my setup, not 0.5 (that WOULD be a significant error). Editing original post.

There would be no need for the author to make any adjustment to the formula because that bias is unique to me based on the malts I use and my water SOP.
It isn’t a universal variance across all users, just for me. I don’t use the included optional tool to adjust for strength of acid malt and until recently it didn’t have a means of taking into account the decrease in pH from the addition of sulfites.
So again, it is proven predictable for me, if I factor in my own system variance, so I am happy with it.
Your mileage may vary, but a predictive tool that has been (in my case anyway) validated as reliable and repeatable is a good tool to me.

And likely since your background is in measurement, no tool is going to be accurate enough for you, and more power to you.
And even if I didn’t adjust for the predictable variance, I can’t tell the difference between a beer that was mashed at 5.32 and 5.37. Maybe you can, but I doubt it.
Or maybe that’s just my confirmation bias (I lukt it up ‘cuz big werds confoose me).

 

[JimRausch]

Covered that in No. 3. Here's the link


https://www.homebrewtalk.com/forum/threads/ph-meter-calibration.302256/

Thank You.

 

[ajdelange]

Let me preface by saying I misspoke with my decimal point. I find BNW to be off by 0.05 pH with my setup, not 0.5 (that WOULD be a significant error). Editing original post.

Hey, it was only one order of magnitude1

There would be no need for the author to make any adjustment to the formula because that bias is unique to me based on the malts I use and my water SOP.
It isn’t a universal variance across all users, just for me. I don’t use the included optional tool to adjust for strength of acid malt

You don't just adjust for the strength of acid malt. Lots of people (including those that write spreadsheets) that because sauermalz is labeled as 3% lactic acid that you can take its weight, multiply by 0.03 and use that amouint of lactic acid in calculations. It doesn't work that way. Sauermalz is a malt and has a titration curve dramatically different from that of lactic acid.and until recently it didn’t have a means of taking into account the decrease in pH from the addition of sulfites.

So again, it is proven predictable for me, if I factor in my own system variance, so I am happy with it.
Your mileage may vary, but a predictive tool that has been (in my case anyway) validated as reliable and repeatable is a good tool to me.

It's repeatable and predictable but my mileage many vary. Got it. The program has several flaws (they all do) some serious and some not so serious. If you are aware of them and can rationalize your way around that then all I can say is "Enjoy!" Of course you really don't have much alternative except to find a better program (and that's going to be tough) or write your own which is really the best option. The tools are freely available to you for the asking but will require you to have at least a rudimentary understanding of what determines pH in a mash.

And likely since your background is in measurement, no tool is going to be accurate enough for you, and more power to you.

Yes, always looking for ways to improve on things, have found them in this arena and continue to strive for even better.

And even if I didn’t adjust for the predictable variance, I can’t tell the difference between a beer that was mashed at 5.32 and 5.37. Maybe you can, but I doubt it.

Nope. And can't tell the difference between one mashed at 144 and 145 either but still buy thermometers with accuracy better than a degree.

Or maybe that’s just my confirmation bias (I lukt it up ‘cuz big werds confoose me).

You have misinterpreted what confirmation bias is. This is something that anyone who votes in an election, makes investment decisions or, in fact, any type of decisions really needs to understand. It is the constant nemesis to the scientist and elaborate protocols have been developed to combat it. If you take nothing else away from this discussion grasp that your life will be much improved if you understand what these "big werdz" mean to you.

I'll close with one final piece of advice. Trust but verify. That's the motto of some intelligence agency and really applies here. Especially verify if you change something e.g. new style of beer, new malt supplier, change in source water alkalinity or, particularly a change in mash thickness (BRUN water is known to have a problem with that).