Brew Day pH results

[micraftbeer]

Palmer's How to Brew (the 4th addition, that was published in 2016 vs his Water book published in 2013 for those wanting to play literary poker...) has a great section on pH and why it's important in your beer. I'm not going to re-type and quote sections of the book (and it's not the copy that's already free on the internet), but I'll summarize. There are 2 key pieces:

1. The pH at the time of saccharification rest is important to the chemical reaction of starch conversion. And since conversion can happen very quickly, he recommends taking your pH sample within the first 5-10 minutes.

2. The pH of the final beer is important in how you perceive and enjoy the taste. There is an interesting graphic showing the stages of pH change throughout the brew process and how it continually falls- during mash, during the boil, during fermentation, and during conditioning. He also references the ideal pH ranges for finished beers like the Weyerman numbers you referenced above in the 4.x range.

 

[ajdelange]

Palmer's How to Brew (the 4th addition, that was published in 2016 vs his Water book published in 2013 for those wanting to play literary poker...) has a great section on pH and why it's important in your beer. I'm not going to re-type and quote sections of the book (and it's not the copy that's already free on the internet), but I'll summarize. There are 2 key pieces:

Five years ago for the Water book? Yes, it was. Seems like yesterday but that's right - it's been 5 years. I wasn't aware that he's done a 4th edition. I would hope that he has incorporated much of what we've learned since then but John does have his own ideas about some things.

1. The pH at the time of saccharification rest is important to the chemical reaction of starch conversion. And since conversion can happen very quickly, he recommends taking your pH sample within the first 5-10 minutes.

He should know better than to recommend that. It is true that starch conversion is controlled by pH and that most of it takes place early on but at 5-10 minutes in you aren't measuring the pH of the mash. You are measuring the pH of the liquor. When the pH reading is 5.4 at 5 minutes what's the pH of the starch? You have no idea except that it is somewhere between the DI mash pH of the grain and 5.4. When the pH stops increasing or decreasing you have at that point a pretty good idea as to what the pH of the mash really is and while that may be too late to take effective corrective action you will at least have a meaningful number to put into your log book for correction of the next batch of this beer you brew.

Again, you are assuming that pH control is about optimizing starch conversion. That may be true for a commercial brewer but for a home brewer you are interested in optimizing overall beer quality and there is more to that than just the amount of alcohol. pH measured when it is stable is a good predictor of beer quality and that is why we measure it when it is stable. In fact, of course, you should measure it at 5 minutes, 10 minutes, 15 minutes 20 minutes and 30 minutes and at conclusion of each mash step or return of each decoction and at knockout and 12 hrs after pitching and of the final beer. In so doing you obtain mileposts along the path to a good beer deviation from which is a valuable diagnostic. After doing this a few times you will be able to predict the eventual stable pH value from an early reading.

2. The pH of the final beer is important in how you perceive and enjoy the taste.

The pH of the final beer doesn't have much influence on the taste. What really determines that is the anion spectrum which is, of course, dependent on pH so in that sense he's right. Brewers control pH of the final product mostly out of consideration for colloidal and microbiological stability.

There is an interesting graphic showing the stages of pH change throughout the brew process and how it continually falls- during mash, during the boil, during fermentation, and during conditioning.

You should be preparing graphs like that in your own brewing (as noted above). It adds to the load but if you are interested in understanding what is going on it is very instructive.

He also references the ideal pH ranges for finished beers like the Weyerman numbers you referenced above in the 4.x range.

Well I have to admit that I knew those were beer pH recommended ranges. But apparently Herr Weyermann didn't.

 

[micraftbeer]

While we were having this conversation, I was brewing beer yesterday and today. And to probably completely go off base what the original poster was after, here's some data from my two brews and pH readings at various points.

Wheat Beer (Saturday)
Did a multi-temperature step mash @ 100 (15 min), 122 (20 min), 150 (60 min), and 168F (10 min).
Didn't do any targeted pH adjustments.
1. pH 5.98 five minutes in of 150F rest.
2. pH 5.86 at end of 150F rest.
3. pH 5.84 after sparge at pre-boil volume in kettle.

IPA (Sunday)
Mashed at 152F (60 min), and 168F (10 min)
Added some phosphoric acid to the mash water to try to hit 5.4 pH (using BeerSmith tool)
1. pH 5.28 five minutes into 152F rest.
2. pH 5.41 thirty minutes into 152F rest.
3. pH 5.43 sixty minutes into 152F rest.
4. pH 5.43 at end of 168F rest.
5. pH 5.44 after sparge at pre-boil volume in kettle.

Now @ajdelange , what you're saying about measuring the pH after it's stable because taking a measurement on a moving target is a guaranteed way to get a lot of variability in your data. And from my data, it looks like pH stabilizes later part-way through the mash and stays there. I guess I'll judge the IPA by the finished beer flavor, and decide later if I was at 5.3 during the mash or 5.4...

 

[ajdelange]

With all the fuss about when to take the pH reading I never got to comment on what you observed.

Below is the data. I don’t know if there is anything useful in it, but never-the-less here it is:

8.5 gallons Ft Worth Water adjusted to Yellow Balanced profile using BS3.
(Ft Worth Water: 44 ppm Ca, 5.3 ppm Mg, 17.8 ppm Na, 29.6 ppm SO4, 23.9 ppm Cl, 126 ppm HCO3)

Sure, there's useful information here from which you might gain some insight. First comment: to get an accurate picture of what the water does we need to know the pH, the alkalinity and the alkalinity titration end point pH. Bicarbonate is OK for an approximate answer as long as your pH is below say 8. Above that error begins to creep in.

The water report they gave you balances really well. So well that I can make the balance perfect by calling the pH 6.1. Since you didn't give me a pH I had to come up with a value and that's as good a guess as any as it doesn't make a whole lot of difference.

5 ml Lactic Acid 88% (Per Bru’n Water)

To tell how much lactic acid is needed we need a good picture of the water and the malts you used. I think we have that for the water though we did have to guess at the pH and alkalinity. Nonetheless we can see that you are going to need about 3.2 mL of 88% acid for the water alone to get to pH 5.4. It's thus quite clear that 5 mL isn't going to be enough.

3 g Epsom Salts (Per BS3)
2 g Calcium Chloride (Per BS3)

Those levels of salt additions aren't enough to make a whole lot of difference. Brun water takes the number from Kolbach's paper which clearly states that it applies to knockout and assumes it applies to the mash tun. As we know that there is pH reduction in the kettle that's clearly not the case. Assuming that all the Kolbach effect takes place in the mash tun you would expect those additions to lower mash pH -0.05 pH. A more realistic answer is probably half that.

4.5 lbs. Flaked Wheat 1.6 SR
.6 oz East Kent Goldings (60 minutes boil)

Now here's where we run into trouble. I surely don't know much about these malts so the best I can do is pick a pale ale malt that has more or less typical characteristics for a pale malt and a wheat malt. Choosing the malt results in an estimated mash pH of 5.67 while choosing the flaked barley results in an estimated pH of 5.48. Thats because the wheat malt I have data on has almost 3 times the proton deficit to pH 5.4 of the flaked barley I have data on.

WY 3068

Love that strain!

I did a full volume BIAB Mash for 90 minutes and added the salts (as recommended in BS3) and 5 ml of Lactic Acid (as calculated in Bru’n Water) before I started to heat the mash water. I added the mash at 154 F and after a thorough stirring the mash temp was 150 F. I checked the pH at the following intervals:

23 Min pH 5.57 cooled to 80 F
55 Min pH 5.66 cooled to 80 F
90 Min pH 5.71 cooled to 80 F
(Room temperature at my house is 72 F)
My pH meter was calibrated just prior to taking the first reading. When it came out higher than expected I cleaned, dried and tested it in the 6.86 solution and it read 6.86. This was repeated in the 4.01 solution and it read 4.01. The wort then retested and again read 5.57.

I am a little suspicious of your pH readings. They shouldn't creep up that much over an hour. I don't know anything about your meter and that's why I recommend a stability check on any meter used for brewing. The details on how to do this check are found in the Stickies at the Brewing Science forum.

Bru’n Water recommended 5 ml of lactic acid for a pH of 5.30 (below 23 Min by .27)
Mash Made Easy predicted that 5 ml would yield a pH of 5.64 (over 23 Min by .07)
BeerSmith 3 predicted that 5 ml would produce a pH of 5.59 (over 23 Min by .02)

To achieve a pH of 5.30:
Bru’n Water recommended 5.0 ml

That's clearly wrong. At pH 5.3 you going to need 3.5 mL for the water alone and 6 -9 for the malt alkalinity depending on whether I pick the worst case or best case malts.

Mash Made Easy recommended 8.78 ml
BeerSmith 3 recommended 10.3 ml

Much more reasonable.

I may have made some errors inputting numbers into the various calculators, but I don’t see them. Next brew day I’ll use MME for lactic acid and report the results.

Don't hang you hat on any of them. As I hope I have made clear here the ability of these to predict depends on how well you know your malts. The first gen calculators make lots of approximations and assumptions. The second gen don't. I used one and I still can't give you a spot on prediction because I don't know your malts.

 

[ajdelange]

Wheat Beer (Saturday)
Did a multi-temperature step mash @ 100 (15 min), 122 (20 min), 150 (60 min), and 168F (10 min).
Didn't do any targeted pH adjustments.
1. pH 5.98 five minutes in of 150F rest.
2. pH 5.86 at end of 150F rest.
3. pH 5.84 after sparge at pre-boil volume in kettle.

IPA (Sunday)
Mashed at 152F (60 min), and 168F (10 min)
Added some phosphoric acid to the mash water to try to hit 5.4 pH (using BeerSmith tool)
1. pH 5.28 five minutes into 152F rest.
2. pH 5.41 thirty minutes into 152F rest.
3. pH 5.43 sixty minutes into 152F rest.
4. pH 5.43 at end of 168F rest.
5. pH 5.44 after sparge at pre-boil volume in kettle.

Now that's normal data! Normal in terms of the variation over time at least. I don' much like 5.84 going into the kettle even for a wheat beer but as the yeast are such great pH reducers maybe you can get away with it.

 

[North_of_60]

Thanks @ajdelange, Let me see if I've got this;

1. The pH of our mash will make its most relevant shift in the first 5 or 10 minutes after the grains and water are combined. BS3 calculated an unadjusted pH of 5.86 and an adjusted pH of 5.57 or a -0.29 shift. This is exactly what my 23 minutes sample tested at. After that the pH will shift but at a much lesser degree. In my case it shifted 0.14 points over an hours time.

2. We are going to wait 25 - 30 minutes to test our target sample as a way of standardizing the test for all home brewers. This will give us a more level playing field. The pH change in my mash only shifted 0.04 points in the last 30 minutes. (If my pH meter was not drifting, more about that later) Whether you are doing a 90 minute mash or a 60 the added pH shift the 90 minute brewer experiences is insignificant.

3. The change in pH during the mash should decrease not increase. This makes sense but, mine increased 0.14 point and one of the micraftbeer examples increased one deceased. ??

Now my pH meter: it is a cheap Amazon meter. I calibrated it using the buffers it came with. I tested it this morning, without recalibrating it, it reads 6.81 in the 6.86 solution and 4.04 in the 4.01 solution. It has been 3 days since I calibrated it and it is drifting. I intend to recalibrate immediately before each use.

Thanks for your patience.

 

[ScrewyBrewer]

It’s goes without saying the age and storage conditions of the calibration solutions are important when trying to get accurate readings.

I use Hanna solutions and keep them refrigerated between use. I also replace the pH bulb every 2 years. Or once the pH readings drift a lot during calibration.

 

[ajdelange]

Thanks @ajdelange, Let me see if I've got this;

1. The pH of our mash will make its most relevant shift in the first 5 or 10 minutes after the grains and water are combined.

Yes.

Thanks BS3 calculated an unadjusted pH of 5.86 and an adjusted pH of 5.57 or a -0.29 shift. This is exactly what my 23 minutes sample tested at.

Not sure what unadjusted and adjusted pH's are but I assume that the former is before adding acid or base to tray to hit a desired pH and the latter the estimate of what happens after that acid or base is added.

[QUOTE="North_of_60, post: 8378927, member: 252777"]After that the pH will shift but at a much lesser degree. In my case it shifted 0.14 points over an hours time.[/QUOTE] Can't say that didn't actually happen but it seems a lot.


[QUOTE="North_of_60, post: 8378927, member: 252777"]
2. We are going to wait 25 - 30 minutes to test our target sample as a way of standardizing the test for all home brewers.[/QUOTE] And for commercial brewers too. At this point there isn't that much interest in pH among commercial brewers but that may be growing. Picking a time does standardize things, of course, but we want to have a measningful stadard. At 25 - 30 minutes things seem to be stable and thus that seems to be a reasonable time at which to measure.

[QUOTE="North_of_60, post: 8378927, member: 252777"]This will give us a more level playing field. [/QUOTE] It gives us the ability to have the pH predictions meaningful. If one uses a good prediction program based on measurements made on the malts when they are stable he can expect a pretty good pH estimate.


[QUOTE="North_of_60, post: 8378927, member: 252777"]
The pH change in my mash only shifted 0.04 points in the last 30 minutes. (If my pH meter was not drifting, more about that later) Whether you are doing a 90 minute mash or a 60 the added pH shift the 90 minute brewer experiences is insignificant.[/QUOTE] You shouldn't see much more than that in an hour.


[QUOTE="North_of_60, post: 8378927, member: 252777"]
3. The change in pH during the mash should decrease not increase. This makes sense but, mine increased 0.14 point and one of the [URL='https://www.homebrewtalk.com/forum/members/micraftbeer.219412/']micraftbeer[/URL] examples increased one deceased. ??[/QUOTE] Sometimes it increases. Sometimes it decreses. Where acid has not been added and calcium is present it tends to decrease. Where acid has been added and calcium is modest or low it tends to increase.


[QUOTE="North_of_60, post: 8378927, member: 252777"]
Now my pH meter: it is a cheap Amazon meter. I calibrated it using the buffers it came with. I tested it this morning, without recalibrating it, it reads 6.81 in the 6.86 solution and 4.04 in the 4.01 solution. It has been 3 days since I calibrated it and it is drifting. I intend to recalibrate immediately before each use.[/QUOTE] Those cheapies are very unpredictable. Sometimes they last 2 years. Sometimes they last 2 weeks. As to how much they may be drifting - that's what the stability test is for.

[QUOTE="North_of_60, post: 8378927, member: 252777"]Thanks for your patience.[/QUOTE]No problem.