Ph- What Reading Should I Have, Is It Consequential?

[peas_and_corn]

Hello all!

Recently I have been interested in pH because... well, I want to. In a recent mash, after the mash in I measured the pH and it measured 4.5. What is the 'ideal' mash pH, what would my reading signify, and what does going either side of the ideal pH do to the beer? How is pH modified? Is it worth spending time tinkering with, or is the improvement not worth the worry?

Cheers,
dave

EDIT: ooh, 2000 posts!

 

[buttersd70]

Theres a nifty ppt presentation in the anhc thread from palmers denver presentation last year which addresses this. 5.4-5.8 at room temperature. Theres also a link in the same thread to palmers chem calculator.

Lots of ways of bringing it up, but one answer would be chalk, which would increase the residual alkalinity as well as upping the calcium. But I'm no mash water guru, you'll no doubt get better advice from others.

I'm surprised that you're coming in so low on adelaide water, though...was it a dark?

 

[peas_and_corn]

Actually no, it was reasonably light coloured, I *believe* that I took it while doing my honey beer.

 

[buttersd70]

:huh:
I was thinking about screwing around with the water, but so many adelaide brewers said that it's good enough not to go through the kerfuffle, and I decided in my own mind that as long as the pH was OK, I wouldn't bother. So I got some strips (not the most accurate, I know), and got 5.2 with my regular grainbill (which gives me about 30EBC beer) and thought, bugger it, good enough....

4.5, though, must have been something in there driving the pH down.

 

[kram]

Are you using tank water or mains supply?

If mains supply, you can obtain a copy of a recent-ish water report which will give you the mean PH amongst other useful information.

 

[peas_and_corn]

Mains water.

How much of an impact would this lowish pH have on the beer?

 

[Gulf Brewery]

HI folks

Was the pH of 4.5 immediate after mash in or after a time interval as it is a bit low and may cause hassles if the pH of 4.5 is correct? Also, did you cool it an measure it or did you measure at mash temperature.

The current water report is here
Get a copy of John Palmers residual alkalinity spreadsheet and see what it estimates for you water pH etc.

Cheers
Pedro

 

[peas_and_corn]

I'm not a scientific man, so I might have measured it wrong- I just dunked the test paper into the mash water

 

[dr K]

Mash pH 4.5 is so not right.
Did you temp comp if you were not using an ATC pH guage?
Did you calibrate before with a known buffer?
Most likely its an incorrect reading rather than a totally screwed water profile...

K

 

[peas_and_corn]

I do not understand your questions.

 

[Stuster]

So give us more information about how you did the test. Did you just dunk some paper into the wort? How sure are you that the colour was right? What range were the pH papers you were using? Did you spit on the papers at any point?

 

[kram]

Did you take the PH reading while it was still hot? If it's a PH strip, it needs to be taken at room temp (20 I think).

 

[peas_and_corn]

I just did the mash in, stirred as usual, and then dunked the usual litmus paper in- it was a 0-14 paper my other half 'borrowed' from uni. It's the paper that has four colours along it. I compared the colours to the guide on the pack. But maybe the high temp interfered and gave a false reading?

 

[buttersd70]

I just did the mash in, stirred as usual, and then dunked the usual litmus paper in- it was a 0-14 paper my other half 'borrowed' from uni. It's the paper that has four colours along it. I compared the colours to the guide on the pack. But maybe the high temp interfered and gave a false reading?

High temp would give a false reading...and also, it might need adjustment for coloured liquids. Most of the papers I've seen around for brewing have the scale on the strip, not on the box, so the coloured liquid effects the scale and the reading similtaneously.

 

[James L]

Temp wouldnt affect the reading on paper pH tests, only the pH probes.

colour of the mash could effect what colour you see on the test strip, but that is highly unlikely. you can always compare the value you see when the strip is wet compared to later on when it is dry, see if it changes..

I use the test strips with the range pH 0-6 or pH 4-7 to give a more accurate result. when you are using such a broad spectrum pH strip (pH0-14), the difference in pH value from the colour change might be harder to determine.

I think you can get them from Merck. Or Uni... if you look in the right place....

Merck pH test strips

 

[katzke]

Temp wouldnt affect the reading on paper pH tests, only the pH probes.

No scientist but everything I have read says PH of wort does change with temp. Something to do with the H atoms or something. The differences I have read would not make that much of a change. I bet it was a problem with the wide range of the paper and reading error.

As to what will happen in the mash with a low PH I am not sure as I have always concentrated on my problem or high PH. It would most likely effect efficiency as the enzymes like that PH range but not sure.