[pmallory]

How do you control the pH, during your mash, once you've measured it. I've heard you add baking soda or salts (gypsum)  to change it. Which one does which? Is there a formula that can tell you how much to add to make it go up or down a certain amount compared to how much grain you have? What is the range you want to keep the pH in? Is this different for different beers? Thanks.

[thcipriani]

What is the range you want to keep the pH in?

I asked that exact same question of A.J. Delange not 2 days ago. Hopefully he won't mind me sharing his answer here because it was the most interesting answer I've gotten on the subject. First, let me share my question since I felt I had to justify asking this question in the first place:

I do have one additional question for you since I have you ear (or, I guess, your eyes) for the moment. Even though its a very simple question (one that I'm almost embarrassed to ask) it's a question that I'd kick myself if I didn't ask. Here are a few quotes that explain my confusion:

Kai Troester, http://braukaiser.com/wiki/index.php/How_pH_affects_brewing :
many authors report wort and beer quality benefits if the pH is lowered into the 5.2 - 5.4 range [Kunze, 2007][Narziss, 2005].
Any mash pH between 5.3 and 5.8 should be sufficient for most mashes
A mash pH between 5.2 and 5.5 is well suited for infusion mashes

Kai Troester, http://braukaiser.com/wiki/index.php/Understanding_Efficiency#pH
optimal mash pH range of 5.4-5.7 (when measured at room temperature)

John Palmer, Zymurgy, Volume 21, No 4, July/August 2008, pg 32
For best results for all [sic] beer styles, the mash pH should be 5.1 to 5.5 when measured at mash temperature, and 5.4 -5.8 when measured at room temperature.

Really, what is the optimum target for the pH of a sample from a mash that has been cooled to 77F? I have been targeting 5.4 since it seems to be acceptable no matter what source you view, but I really don't have any idea. I know that there is a pH difference between hot and room temperature samples but is there some difference between samples that have never been heated vs. samples that are heated and then cooled?

A.J.'s reply was:

That's a very good question but one that does not, unfortunately, have an answer. When asked I usually tell about the Jean DeClerck Chair, given every two years by, the Catholic University of Louvain (jointly, by the Flemish and Wallon schools into which the original split). The year I attended the session was titled "The pH Paradox". Over three days of presentations the subject of pH in brewing gone over with respect to mash, stability, flavor, colloids etc. The title was chosen, of course, because even in a single area, such as mash pH,  there is range of workable pH's. As you well know alpha amylase is most active at one pH while beta is most active at another. Which pH is the "best" for any particular beer is, IMO, only determinable by repeatedly brewing the beer at various pH's and seeing what produces the best beer. This is, of course, what a commercial brewer does either explicitly, by taking measurments, or implicitly by changing the amount of acid he adds to the mash and tasting. Anecdotal evidence is not the best way to draw a conclusion but I will say that the biggest single improvement in my brewing in the last 5 years or so came when I started actively controlling pH to between 5.3 and 5.4 (room temperature) rather than just monitoring it.

As to your other questions I'll go with the only one I'll be able to answer with any level of certainty:

I've heard you add baking soda or salts (gypsum)  to change it. Which one does which?

Baking soda (the HCO3 in baking soda) raises pH, gypsum (the Ca++'s reaction with malt phosphates [Hydrogen Phosphates, mainly, according to Fix]) lowers pH in the mash.

[chezteth]

I definitely agree with what thcipriani is saying.  The most common number I have usually heard is a pH of 5.2.  I generally don't worry too much about the pH as long as it is within a small range from 5.2

Happy Brewing,
Brandon

[hopfenundmalz]

I am no AJ deLange, but I will add a couple things.

You can lower the pH by adding Calcium, as stated.   
You can raise pH pH by adding CaCO3, as stated.

Minerals common in homebrewing:
CaSO4 (gypsum) lowers pH, and adds SO4 which adds to the hop perception.  Use for hop focused beer like IPA.
CaCl2 (Calcium Chloride) lowers the pH and adds Chloride which enhances malt perception.  Use for malt focused beers like Bock.
CaCO3 (Calcium Carbonate, or chalk) raises the pH.  Note that adding the carbonate also adds calcium, so you are taking the pH higher, but the Ca addition impeeds how much it goes up.
NaHCO3 (Sodium bicarbonate), or baking soda) will raise the pH, without adding Ca.
MgSO4 (Epsom Salt) do not change the pH of the mash, adds to SO4 total.  Mg is beneficial for yeast at 10-20 ppm.
NaCl (Salt) does not change pH.  Adds to Cl total.
Some people pay attention to the ratio of SO4 to Cl.  >1 for hoppy, <1 for Malty.

Acids can also be used to lower the pH.  Lactic acid and Phosphoric acid are the ones most homebrewers use.

If the pH in the mash gets over 5.8, the mash efficiency suffers and falls off quickly with higher pH.  I saw this in at graph at a presentaion about mashing.

One last thing, you need to know your base water mineral content before you start to really adjust your water for different styles.

[Thirsty_Monk]

[tom]

John Palmer's book How To Brew was the first to help me get an understanding of mash pH. You can see his on-line version at http://www.howtobrew.com/section3/chapter15-3.html

[wingnut]

+1 on the How to Brew reference.

However, there is a product on the market made by Five Star Chemicals called  “5.2 Stabilizer”.  Essentially, it adds buffers to the mash to keep your PH at 5.2.   It kind of takes the guess work out of how much salts/acids to add.   I have used it and it works as advertised. 

I have read a few people say that 5.2 Stabilizer does not work well, but that is consistently due to them adding it to their water and expecting a PH change.   5.2 Stabilizer needs the malt in order for the buffers to perform correctly.   

Good luck

[tom]

pH 5.2 is designed to decrease the mash pH in pale beers. It doesn't work at all for increasing mash pH in dark beers in my experience.

[denny]

And in my experience it doesn't always work in pale beers, either.  If you use it, you should check your pH and not just assume it's correct.

[bluesman]

And in my experience it doesn't always work in pale beers, either.  If you use it, you should check your pH and not just assume it's correct.

+1

I think you need to understand your specific water chemistry.  Have your water tested and mke predictions and adjustments based from that.

[wingnut]

[

pH 5.2 is designed to decrease the mash pH in pale beers. It doesn't work at all for increasing mash pH in dark beers in my experience.

Hmmm, I guess  I should have considered that my "Vienna like" water that I get from my tap may have influenced my success...

And I totally agree to test the PH a few times during the mash.  I usually test every few minutes after dough in to be sure I have enough 5.2 added. (or as I would do in my pre-5.2 days... add acid)

I also recommend using Palmers_Mash_RA.xls spread sheets to dial in your water to where you want it.   

What I have found is that with my hard water with a high residual alkalinity... if I use 50% my water mixed with 50% distilled water, for some lighter beers, (such as cream ales or pale ales)  I find that I do not have to add any 5.2 (or salts/acids) to the water to keep the PH where it needs to be... HOWEVER, I did not know I could do that until I played with the spread sheet a bit... In fact, just plugging in numbers and seeing what happens when you add this or that salt to your water really helps to understand the whole picture.

Good luck!

[johnf]

+1 on the How to Brew reference.

However, there is a product on the market made by Five Star Chemicals called  “5.2 Stabilizer”.  Essentially, it adds buffers to the mash to keep your PH at 5.2.   It kind of takes the guess work out of how much salts/acids to add.   I have used it and it works as advertised. 

I have read a few people say that 5.2 Stabilizer does not work well, but that is consistently due to them adding it to their water and expecting a PH change.   5.2 Stabilizer needs the malt in order for the buffers to perform correctly.   

Good luck

It doesn't work for me in mash experiments. I'll be happy to try to replicate any experiment you have done with a positive result (including matching the water you used if you provide that info). I suspect you aren't using a freshly calibrated pH meter though, and that is why our observations are different.

Note that in order for 5.2 to work as advertised, it would have to actually change the pH of water 5.2 (check the advertising claims).