Kettle PH

Yes, there is published evidence in Malting and Brewing Science in the form of a graph. Unfortunately, my volumes of that text are at home and I can't cite the figure number. Wort gravity has a major influence in tannin and silicate extraction.

When I mentioned 'somewhat regardless' for the pH, that was assuming that the wort pH was not wildly out of range (<6). If it is higher than that, there will be other problems that will affect the beer.

Mine are also 600 miles away so I can't check. In interim you will have to color me very skeptical as I can't think of any physical phenomenon that would induce 'major' influence. I have listed the things it shouldn't be in a previous post. Perhaps there is some phenomenon that I haven't heard of that would explain it.

I brewed yesterday and decided to keep up with everything. Brewday was kind of a mess, so I am trying to record all kinds of info and get in a rhythm. The recipe was a modified lil sparky nut brown:

2.25 Gallon Batch (BIAB)
100% Distilled Water
Starting volume = 3.60 gal

3.304 lbs Marris Otter
0.367 lbs Flaked Oats
0.184 lbs Victory
0.367 lbs Crystal 60
0.092 lbs Chocolate

0.39 oz Fuggles @ 4.7% & 60 Min
0.33 oz East Kent @ 6.3% & 15 Min

S-05 Yeast

1.1 grams Gypsum
1.1 grams Calc Cl
1.0 mL Lactic Acid

I have a MW-102 pH Meter. I calibrated it 3 times throughout the process. I used Brunwater and input my Marris Otter, Oats, and Victory, along with my salts and acid and had a predicted mash pH of 5.45.

1. Initial Distilled Water pH = 4.39
2. Initial Distilled Water with salts and acid = 3.59

Mash pH

3. 15 min = 5.29 @ 88 deg F (No Crystal or Choc)
4. 30 min = 5.33 @ 89 deg F (No Crystal or Choc)
5. 45 min = 5.33 @ 88 deg F (No Crystal or Choc)
6. 60 min = 5.37 @ 82 deg F (No Crystal or Choc)

Mashout pH (added chocolate and c60 at start of ramping to 168-170 deg. this took 35 minutes. due to this taking so long, I only did a 5 min mashout. 0 min is the start of 168 deg F)

7. 0 min = 5.25 @ 82 deg F (all Malts)
8. 5 min = 5.21 @ 84 deg F (all Malts)
9. After Squeeze of bag = 5.15 @ 80 deg F (all Malts)

Kettle pH

10. 15 min = 5.16 @ 80 deg F
11. 30 min = 5.10 @ 67 deg F
12. 45 min = 5.05 @ 80 deg F
13. 60 min = 5.08 @ 80 deg F

14. Post Chill pH = 5.10 @ 67 deg F

So there's 14 pH readings. Its definitely overkill, but I was interested in how it reacts throughout the process. I assume around 80-90 deg is okay to take a pH reading? If not, is there a conversion to room temp Ph?

After a few readings I put the probe back in the buffer solutions. It was always within +/- 0.03 of the buffer....except for the #1 and #2. They were -0.05 off.

Ive attached my spreadsheet that has everything.

View attachment Nut Brown 2xml.xml

ParanoidAndroid said:

So there's 14 pH readings. Its definitely overkill, but I was interested in how it reacts throughout the process.

Click to expand...

And now you have a pretty good idea of how it changes during the process so it wasn't overkill at all. Do this a few more times to get a feel for what kind of variation you can expect from batch to batch and for different styles of beer. From there on a check at a couple of points should suffice.

ParanoidAndroid said:

I assume around 80-90 deg is okay to take a pH reading?

Click to expand...

It is and it isn't. If you do take measurements at an elevated temperature you will shorten the life of your electrode because of the thermal stresses temperature change puts on it. Also, if you measure at temperature other than the calibration temperature you rely on your meter's ATC algorithm which is only dead nuts on if the electrode's isoelectric pH is 7 and no meter I know of allows you to adjust if it isn't (which is why I do ATC in my computer). If you plan to measure at elevated temperature you should calibrate at elevated temperature too.

ParanoidAndroid said:

If not, is there a conversion to room temp Ph?

Click to expand...

It depends on the temperature offset. I have used 0.0055 pH/°C only to find that it is malt dependent. This is why most people simply use room temperature pH readings.