Author Topic: PH question  (Read 2087 times)

Offline greatplainsbrewer

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PH question
« on: April 22, 2012, 08:42:00 AM »
Just tested the PH on an ordinary bitter mash.  Mash tested at 5.4 at 66F.  Not that I'm real worried about it but Bruunwater estimated my mash PH at 5.2.  I am planning on doing at least one batch of BoPils this summer and would like to be able to hit a low mash PH.  I seem to consistently run .2 high.  I have a recent Ward labs water test and I use a Hanna PH meter that was calibrated this morning.  Any thoughts?

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Offline deanocamino

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Re: PH question
« Reply #1 on: April 22, 2012, 09:06:19 AM »
I too have had the same issue, I just used bru n water for the first time just the other day and my ph was estimated to come in around 5.3 and it came in at 5.5.  I guess the few decimal points is not going to screw the beer up but I was curious why that happened. My initial thought was that my ph meater was off, so I recalibrated it just to make sure, and that was not the case. I do however remember my samples being a bit below the recomended range of 77f or 25c. it was more ln the 60's, so I could only guess that is why it came out off like that.  I am going to brew again on saturday and will pay a bit more attention to the temps and see if that helps any.

I dont know if this happend to you as well but I used phosphoric acid in my sparge water to drive ph down. A buddy of mine told me just to use half of the recomeneded amount of the spread sheet cause he was coming in way low... so I did and it only drove it down a few points so I added the rest waited about 15 minutes or so tested it again at the right temp both times, and it sayed the same. I did not take into account the "dead" space my kettle has due to the placement of the spout.  But I think it should of dropped it down further then it did.  Did this happen to you as well?

Offline narvin

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Re: PH question
« Reply #2 on: April 22, 2012, 09:44:05 AM »
I wouldn't worry at all.  First of all, when measuring at room temperature, 5.4 is just about where you want to be.  Water spreadsheets are just a way to estimate what your pH will be, and the actual result will vary, often by a lot.  If you look at the lot analysis for malt online, you can see that even the same base malts produce mashes of different acidity from lot to lot.  If you are trying to hit a certain pH and it measures higher than you want, use the calculator to estimate how much lactic or phosphoric acid you need to drop by 0.1, add that, and measure again.  Repeat if necessary.
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Offline narvin

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Re: PH question
« Reply #3 on: April 22, 2012, 09:47:52 AM »
I dont know if this happend to you as well but I used phosphoric acid in my sparge water to drive ph down.  A buddy of mine told me just to use half of the recomeneded amount of the spread sheet cause he was coming in way low... so I did and it only drove it down a few points so I added the rest waited about 15 minutes or so tested it again at the right temp both times, and it sayed the same. I did not take into account the "dead" space my kettle has due to the placement of the spout.  But I think it should of dropped it down further then it did.  Did this happen to you as well?

Was he measuring the pH of the sparge water itself?  Once the buffering capacity of the alkalinity is neutralized, the pH of the water will drop quickly, but this doesn't matter.  It's the total amount of acidity that matters, which is why you want to measure the pH in the mash or in your kettle, not the pH of your water.
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Offline nateo

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Re: PH question
« Reply #4 on: April 22, 2012, 09:56:07 AM »
Getting within 0.2 of your target pH is incredibly accurate for a spreadsheet. That's why I like Bru'n water so much. I always doublecheck with a meter.

Mash pH is one of the last mostly unexplored parameters. I know Martin has mentioned this before. For instance, a beer with a mash pH of 5.2 will taste different than the same beer at 5.5. The exact differences haven't really been explored on a homebrew scale.
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Offline deanocamino

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Re: PH question
« Reply #5 on: April 22, 2012, 10:29:46 AM »

[/quote]

Was he measuring the pH of the sparge water itself?  Once the buffering capacity of the alkalinity is neutralized, the pH of the water will drop quickly, but this doesn't matter.  It's the total amount of acidity that matters, which is why you want to measure the pH in the mash or in your kettle, not the pH of your water.
[/quote]

Not to jack the thread so I appologize....

This was the first time I have dont this "acid" thing, my buddy said to add it directly to the sparge water, so what I am understanding is.  Do not take the ph of the acutual sparge water, take the ph of the water after mixed it in with the grains during you batch sparge?

Offline narvin

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Re: PH question
« Reply #6 on: April 22, 2012, 10:56:31 AM »

Not to jack the thread so I appologize....

This was the first time I have dont this "acid" thing, my buddy said to add it directly to the sparge water, so what I am understanding is.  Do not take the ph of the acutual sparge water, take the ph of the water after mixed it in with the grains during you batch sparge?

Yes, it's easier just to make sure your batch sparge isn't above pH 5.5, since this is the goal when acidifying sparge water.  The idea is that if you neutralize the alkalinity in the sparge water with acid, and your mash pH is correct, the sparge itself shouldn't go above 5.5 and you will be less likely to extract tannins from the grain.  Small additions of acid can result in large pH swings in the sparge water, so I don't think measuring the water pH is useful.  You can still use your water spreadsheet's estimate and add the acid directly to the sparge water.
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Offline narvin

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Re: PH question
« Reply #7 on: April 22, 2012, 11:04:18 AM »
Getting within 0.2 of your target pH is incredibly accurate for a spreadsheet. That's why I like Bru'n water so much. I always doublecheck with a meter.


Part of this is due to the magic of buffering capacity of the mash.  In my experience, most mashes, even from the extremes of stout to pilsner, naturally fall in between 5.5 and 5.7 without any adjustments with a moderately soft water!  I've noticed that I actually need significantly more acid to bring the pH down to 5.4 than spreadsheets predict, while the contribution from dark malts is overstated by spreadsheets and less likely to bring you below 5.4 than you think.  Basically, it's pretty hard to screw up your mash pH unless you have high bicarbonate water.
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Offline mabrungard

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Re: PH question
« Reply #8 on: April 22, 2012, 11:09:14 AM »
I'm not surprised by the results mentioned above.  With very good control on the water quality and ingredients, you could find that the actual pH is more typically a tenth or two higher than the prediction based on my observations.

With additional mash pH observations from me and my beta team, the pH prediction algorthym has been updated for the next version.  But that prediction only moves the pH up by about a tenth in most cases.  I purposely want users to predict a slightly lower pH than actual than have it higher.  I find that this is a safer result for most users. 

Don't expect that a program can nail the pH prediction every time since there are too many variables that can skew the results.  If the water quality varies or if the malt acidity varies, the prediction is likely to differ.  Getting within a couple of tenths is pretty good.  I think the next version will help get the predictions closer, but that won't alter the fact that ingredient variability could screw it up.

Enjoy!

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Offline mabrungard

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Re: PH question
« Reply #9 on: April 22, 2012, 11:13:15 AM »
Narvin, everything you mention regarding your observations suggests that your water actually has more alkalinity than you are inputing in whatever program you're using.  Have you confirmed the alkalinity value you use?
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Offline nateo

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Re: PH question
« Reply #10 on: April 22, 2012, 11:14:48 AM »
Part of this is due to the magic of buffering capacity of the mash.  In my experience, most mashes, even from the extremes of stout to pilsner, naturally fall in between 5.5 and 5.7 without any adjustments with a moderately soft water! 

Yeah, I can't remember the last time I actually had to raise the alkalinity in my water, even with lots of roasted barley. Whenever I see anyone planning on adding chalk or lime to their mash, little alarm bells start ringing in my head. My water (lime treated) still has a decent amount of alkalinity, but even with just pils mashes, they usually fall in at the high end (5.8-5.9) but I've never seen a mash over 6.
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Offline tom

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Re: PH question
« Reply #11 on: April 22, 2012, 11:31:15 AM »
How are you testing the pH?
As Narvin said, the mash pH value at room temperature is 0.2-0.3 higher than at mash temperature.

Just tested the PH on an ordinary bitter mash.  Mash tested at 5.4 at 66F.  Not that I'm real worried about it but Bruunwater estimated my mash PH at 5.2.  I am planning on doing at least one batch of BoPils this summer and would like to be able to hit a low mash PH.  I seem to consistently run .2 high.  I have a recent Ward labs water test and I use a Hanna PH meter that was calibrated this morning.  Any thoughts?

Thanks
Brew on

Offline greatplainsbrewer

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Re: PH question
« Reply #12 on: April 22, 2012, 12:04:26 PM »
Thanks for the replies, great board.

I hope I didn't come off as complaining about Bruunwater- great tool, thanks Martin it has greatly increased my understanding of what is in my water and how it affects the mash.  My beer looks and tastes better.  I was worried about my technique.  I was thinking that it might be correctable.  I think in the future I'll try to adjust to account for the pH being a little high.

Offline narvin

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Re: PH question
« Reply #13 on: April 22, 2012, 12:54:15 PM »
Narvin, everything you mention regarding your observations suggests that your water actually has more alkalinity than you are inputing in whatever program you're using.  Have you confirmed the alkalinity value you use?

I've checked the yearly water report and sent samples to Ward Labs.  The flipside of what I mentioned before is that an amber ale with very minimal calcium additions hits 5.5 in the mash as predicted.

This is measured with a Milwaukee pH meter.  pH strips, even the colorphast, read low for me in comparison on dark beers like stout, even after taking into account the systematic error Kai found in his experiment.
« Last Edit: April 22, 2012, 01:04:38 PM by narvin »
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