Basic Ph Question

[Superoo]

I would like to start down the path of checking my water quality, I use rain water, PH of the water is 7.1 at the moment.
I havent had any samples done, but intend to do so later.

But before getting my head into it too far, I would just like to know the basics of PH testing, and what PH levels are suitable for a standard mild ale, light in colour, using mostly pale malt.

I have read some documentation including 'key concepts in water treatment', but its all abit confusing until you actually get started down the path, and I'm not even sure how I should be sampling.

As a first step, I have purchased an el-cheapo PH meter, and it works fine, I can calibrate it etc using the test sachets supplied, no probs there.
So I would like to get my testing routine in order before I try and get a grip on the products used to adjust PH etc.

I am a BIAB'er, (I admitted it at a meeting last night, that was a big step forward)

I would like to know
1- At what points during the brew process should I check the PH.
2- Roughly what readings I should be aiming before and during the mash for this beer.
3- What method should I use to check during the mash, is it as simple as taking a small sample, cooling it and testing ?

Any info would be appreciated.

Cheers,
Chris

 

[kevin_smevin]

I would like to start down the path of checking my water quality, I use rain water, PH of the water is 7.1 at the moment.
I havent had any samples done, but intend to do so later.

But before getting my head into it too far, I would just like to know the basics of PH testing, and what PH levels are suitable for a standard mild ale, light in colour, using mostly pale malt.

I have read some documentation including 'key concepts in water treatment', but its all abit confusing until you actually get started down the path, and I'm not even sure how I should be sampling.

As a first step, I have purchased an el-cheapo PH meter, and it works fine, I can calibrate it etc using the test sachets supplied, no probs there.
So I would like to get my testing routine in order before I try and get a grip on the products used to adjust PH etc.

I am a BIAB'er, (I admitted it at a meeting last night, that was a big step forward)

I would like to know
1- At what points during the brew process should I check the PH.
2- Roughly what readings I should be aiming before and during the mash for this beer.
3- What method should I use to check during the mash, is it as simple as taking a small sample, cooling it and testing ?

Any info would be appreciated.

Cheers,
Chris

Check pH about 5 min into mash - ideal procedure would be to take a sample and filter through filter paper, cool the wort to room temp and measure pH. You're looking for a pH in the range of 5.2-5.6. Some texts advocate pH below 5.2 (5.0-5.2) as it inhibits the lipoxygenase enzyme which plays a role in beer staling. I would try not to get above 5.6 though.

Check at the end of boil - take sample and cool to room temp. This is just for your records and to note any differences between brews. Not really that important just might be interesting to note.

Check post fermentation - here your looking for a pH between 4.4-4.6 from memory. This is important as it influences the stability of your beer and its ability to clear etc.

Always test pH of your samples at about the same temp. Try and use about room temp (20-25) as this will preserve the life of your pH probe.

 

[Superoo]

Thanks heaps, thats exactly the answer i needed.

Much appreciated.

 

[Wolfy]

If you have a working pH meter, my two el-cheapo ones broke before they could be any use (and one before it was even calibrated), the following informaiton provided to me by BrewLab (in the UK) might be of interest:

When you are actually brewing check the pH in the incoming water, the
treated water, the mash liquor, then the first worts, worts pre and post
boil (cooled) and then the final fermented product. You can then compare
them to the standard pH values in the table below and they should be
within the normal ranges.



Part of brewing process Normal pH range


Raw liquor 6.8 - 8.0
Treated liquor 6.5 - 7.0
Mash 5.2 - 5.5
1st runnings 4.8 - 5.2
Last runnings 5.4 - 5.6
Wort pre boil 5.1 - 5.4
Wort post boil 4.9 - 5.3
Final product 3.9 - 4.2

 

[jayse]

It is important to note the intial PH of the water you will use means very little, most tap water is around about the same mark but its not the actuall PH your interested in here but the make up of the water is what you need to use to predict what PH you will get in the mash.

 

[Superoo]

Awesome, all of your replies will get me learning.

Thanks heaps.

 

[felten]

These are great if you haven't read them yet.

http://www.braukaiser.com/wiki/index.php/An_Overview_of_pH
http://www.braukaiser.com/wiki/index.php/H...affects_brewing
http://www.braukaiser.com/wiki/index.php/Mash_pH_control

 

[rowanb]

Nice introduction to water treatment from AJ DeLange over at homebrewtalk

 

[malt_shovel]

Check pH about 5 min into mash - ideal procedure would be to take a sample and filter through filter paper, cool the wort to room temp and measure pH. You're looking for a pH in the range of 5.2-5.6. Some texts advocate pH below 5.2 (5.0-5.2) as it inhibits the lipoxygenase enzyme which plays a role in beer staling. I would try not to get above 5.6 though.

Check at the end of boil - take sample and cool to room temp. This is just for your records and to note any differences between brews. Not really that important just might be interesting to note.

Check post fermentation - here your looking for a pH between 4.4-4.6 from memory. This is important as it influences the stability of your beer and its ability to clear etc.

Always test pH of your samples at about the same temp. Try and use about room temp (20-25) as this will preserve the life of your pH probe.

I am of the understanding that pH varies with temperature, and the pH of the mash is what is important. I don't think pH meters like being cooked at mash temps which is one of the reasons i don't have one. I can't recall which way it swings, but I think higher temps give a lower pH.
I am sure a chemist on this forum can confirm. Probably within the noise of the measurements we make, but I would prefer a pH strip measured in the mash vessel at mash temps over a sample cooled to room temps with an electronic meter.

 

[felten]

"For wort it has been reported that the pH at mash temperatures (65 C/150 F) is about 0.35 pH units lower than at room temperature and at mash out temperatures (75 C/170 F) it is even 0.45 pH units lower [Briggs, 2004]. While my own experiments showed only a ~0.2 pH difference between a sample at mash temperature and a sample at room temperature (25 C/77 F)."

From the braukaiser overview of pH page.