50 replies to this topic

[matt6150]

Those look to be in the ballpark. If you want to send me your spreadsheet, I'll be happy to look at it for you.To raise mash pH you add something alkaline like baking soda or pickling lime. Chalk used to be recommended for this but after reading Water, I'll never use it again.

Well I just mashed in, I would have sent it to you but I'm on my phone now away from my computer, but thanks though.

 

Looks like I'm in the ballpark with the mash ph. I put the strip in for about 10 sec and it matched the 5.0 on the color chart almost spot on, maybe slightly higher but its hard to tell and the next color up is 5.3 so not the most accurate. 

[matt6150]

Don't forget to account for the built in error you get from the ColorpHast strips. They will read 0.3-0.35 lower than actual pH at room temperature.

Yeah I did remember that, thanks! Why is that btw, they don't say this anywhere when you buy them. Where does this info come from?

[Big Nake]

Yeah I did remember that, thanks! Why is that btw, they don't say this anywhere when you buy them. Where does this info come from?

I think it's an ATC thing.  It compensates for the temp if you measure at mash temp (which I did when I used the strips).  That suggests that if you allowed the mash sample to cool to room temp and took the reading with the strip, the .3 correction factor goes out the window.  Anyone feel free to correct me if I'm off on that.

[MtnBrewer]

I think it's an ATC thing.  It compensates for the temp if you measure at mash temp (which I did when I used the strips).  That suggests that if you allowed the mash sample to cool to room temp and took the reading with the strip, the .3 correction factor goes out the window.  Anyone feel free to correct me if I'm off on that.

I think that's right but that's not an ATC thing. That's a true change in pH from room temperature to mash temperature.

[MyaCullen]

I think that's right but that's not an ATC thing. That's a true change in pH from room temperature to mash temperature.

 

so the same would be true no matter the measuring method? the pH will become lesser as the sample cools?

 

so are we shooting for the pH to be correct at mash temp or corrected to RT, getting more confused now 

[MtnBrewer]

so the same would be true no matter the measuring method? the pH will become lesser as the sample cools?

No, the pH goes up as the sample cools. 

so are we shooting for the pH to be correct at mash temp or corrected to RT, getting more confused now 

Both. Obviously at mash temp is where we want it to be correct but since we usually have to measure at room temp, we apply about a 0.3 pH offset to compensate for the change in temperature. However, this is NOT ATC.

[MyaCullen]

No, the pH goes up as the sample cools. Both. Obviously at mash temp is where we want it to be correct but since we usually have to measure at room temp, we apply about a 0.3 pH offset to compensate for the change in temperature. However, this is NOT ATC.

ATC is a correction factor built into some meters

[positiveContact]

colorphast strips are apparently magical and they can measure the same hot or cold

 

i just stick the strip into the mash.

[MtnBrewer]

ATC is a correction factor built into some meters

 Right. But the important point is that it is a correction to compensate for the non-linearity of the meter wrt temperature. It's not a correction for the .3 pH differential due to the temperature difference between room temp and mash temp. 

colorphast strips are apparently magical and they can measure the same hot or cold

That probably isn't a good thing. They should read .3 pH higher at room temp. If they don't then that calls into question their accuracy.

[positiveContact]

 Right. But the important point is that it is a correction to compensate for the non-linearity of the meter wrt temperature. It's not a correction for the .3 pH differential due to the temperature difference between room temp and mash temp. That probably isn't a good thing. They should read .3 pH higher at room temp. If they don't then that calls into question their accuracy.

 

quote from kai on HBT:

 

It matters bc a meter shows a different pH at mash temp (about 0.2 lower) while the strips have the same color reaction at mash and room temp.

[MyaCullen]

quote from kai on HBT:

as far as strips go I actually use Varn brand strips, wonder if that factors in.

[positiveContact]

as far as strips go I actually use Varn brand strips, wonder if that factors in.

 

i've only used colophast (which seems prety good) and some other brand which seemed useless.

[Big Nake]

Can we agree that if you have a meter and the meter is showing you its reading (at whatever temp), you can treat that reading as gold because the meter is correcting for temp?  On my meter, it shows the pH, the current temp of the sample and up in the corner "ATC" is flashing telling me that if the meter says 5.3, the pH is 5.3 regardless of the temp of the sample.  I leave the meter in the sample for a good 5-10 mins (or until it shuts itself off) just to see if it changes.

 

EDIT:  OMG, who changed my board "title" to Comptroller of H2O?  That is a HUGE stretch. 

Edited by KenLenard, 29 October 2013 - 11:20 AM.

[neddles]

Can we agree that if you have a meter and the meter is showing you its reading (at whatever temp), you can treat that reading as gold because the meter is correcting for temp?  On my meter, it shows the pH, the current temp of the sample and up in the corner "ATC" is flashing telling me that if the meter says 5.3, the pH is 5.3 regardless of the temp of the sample.  I leave the meter in the sample for a good 5-10 mins (or until it shuts itself off) just to see if it changes.

 

EDIT:  OMG, who changed my board "title" to Comptroller of H2O?  That is a HUGE stretch. 

Ken I think the pH is 5.3 at whatever temperature your meter is compensating to. But the actual pH is not the same regardless of the sample temp. Also if I am remembering correctly you are cooking the life out of your probe by measuring at mash temperature instead of cooling first (at which point you won't need the ATC). Someone else chime in if I am misstating this.

 

BTW you are the perfect Comptroller of H2O.

[Big Nake]

Ken I think the pH is 5.3 at whatever temperature your meter is compensating to. But the actual pH is not the same regardless of the sample temp. Also if I am remembering correctly you are cooking the life out of your probe by measuring at mash temperature instead of cooling first (at which point you won't need the ATC). Someone else chime in if I am misstating this.

 

BTW you are the perfect Comptroller of H2O.

Well, I take a sample of the mash and put it into a glass I just took out of the freezer and I let the sample sit for a few minutes before I put my meter in there.  The temp is usually in the 90-105 range when I place the meter in there so I wouldn't expect that to cause any real damage to the probe but I could be wrong. 

 

I don't know, "comptroller of water curiosity" or "comptroller of worrying far too much about water" or "comptroller of generally whiffing on water chemistry" seems more accurate. 

[neddles]

Well, I take a sample of the mash and put it into a glass I just took out of the freezer and I let the sample sit for a few minutes before I put my meter in there.  The temp is usually in the 90-105 range when I place the meter in there so I wouldn't expect that to cause any real damage to the probe but I could be wrong. 

 

I don't know, "comptroller of water curiosity" or "comptroller of worrying far too much about water" or "comptroller of generally whiffing on water chemistry" seems more accurate. 

Sorry I misinterpreted what you were saying about your process there. My bad. I would "guess" you are fine at 90-105F.

[neddles]

I am going to muse for a moment about pH and the strips just so I am clear on my understanding.

 

According to Water the proper room temp. pH is 5.2-5.6. Because pH drops as you heat it the proper pH at mash temp is 0.2 lower than at room temperature giving you a proper mash temp pH of 5.0-5.4. Correct?

 

Now the colorpHast strips will give you lower reading than actual (at room temp.) by a factor of 0.3. Kai documented this clearly on his website. So proper room temp pH with these strips should show 4.9-5.3. However he says nothing there about using the strips at mash temp. and what you should expect. Theoretically you would expect the strips to give you 4.7-5.1 for proper pH at mash temp. but the quote Studs provided from Kai on HBT is throwing me off. "[color=rgb(40,40,40);font-family:helvetica, arial, sans-serif;font-size:12px;background-color:rgb(247,247,247);]the strips have the same color [/color][color=rgb(40,40,40);font-family:helvetica, arial, sans-serif;font-size:12px;background-color:rgb(247,247,247);]reaction[/color][color=rgb(40,40,40);font-family:helvetica, arial, sans-serif;font-size:12px;background-color:rgb(247,247,247);] at mash and room temp."[/color]

It's the first I have seen of this. If it is true, the proper mash temp pH as measured on the strips should be 4.9-5.3 right? for you guys who just dip them in the mash are you leaving them in there at that temp for the entire 2 minutes recommended on the case? 

[positiveContact]

ken, i think using your meter in really hot liquid will shorten the probe life.  could be wrong on that.

[positiveContact]

I am going to muse for a moment about pH and the strips just so I am clear on my understanding.

 

According to Water the proper room temp. pH is 5.2-5.6. Because pH drops as you heat it the proper pH at mash temp is 0.2 lower than at room temperature giving you a proper mash temp pH of 5.0-5.4. Correct?

 

Now the colorpHast strips will give you lower reading than actual (at room temp.) by a factor of 0.3. Kai documented this clearly on his website. So proper room temp pH with these strips should show 4.9-5.3. However he says nothing there about using the strips at mash temp. and what you should expect. Theoretically you would expect the strips to give you 4.7-5.1 for proper pH at mash temp. but the quote Studs provided from Kai on HBT is throwing me off. "[color=rgb(40,40,40);font-family:helvetica, arial, sans-serif;font-size:12px;background-color:rgb(247,247,247);]the strips have the same color [/color][color=rgb(40,40,40);font-family:helvetica, arial, sans-serif;font-size:12px;background-color:rgb(247,247,247);]reaction[/color][color=rgb(40,40,40);font-family:helvetica, arial, sans-serif;font-size:12px;background-color:rgb(247,247,247);] at mash and room temp."[/color]

It's the first I have seen of this. If it is true, the proper mash temp pH as measured on the strips should be 4.9-5.3 right? for you guys who just dip them in the mash are you leaving them in there at that temp for the entire 2 minutes recommended on the case? 

 

i leave it in there for probably 30 seconds and pull it out.  i have always noticed that i am near what the spreadsheet predicted so I say it's good

[MtnBrewer]

Can we agree that if you have a meter and the meter is showing you its reading (at whatever temp), you can treat that reading as gold because the meter is correcting for temp?

Yes if it's an ATC meter. Take a sample at, say, 120°F then let it cool down to room temp and you'll see that it's higher.