Ph Readings All Over the Place

[ALD]

Hi. Apologies for the long post before hand. I wanted to share as much data that may help narrow down the issue.

I will begin by stating that other than not hitting the FG in most of these beers by about 5 points (which could be caused by a number of variables), the beers have all tasted good. I just don't understand why the Ph readings are so far off. Below are different beers, target Ph per BrunWater and actual readings.

I appreciate any insight, what could be the cause, how can I get more consistent in hitting the 5.2-5.4 range.

Thank you!!

Batch Sizes ~30 liters
Water Profile Ph 6.9-7.1

Samples are collected at the indicated times, readings usually take place during the boil, about 60 mins after when all samples have cooled down. I've include a picture of the PhMeter, not a high quality device, but when reading the control substance a chemist friend prepares, it is within 0.1 from the control figure.

RED IPA (Brewed twice)
Target Mash PH per BrunWater with salt adjustments: 5.2
Water to Grist L/Kg 2.6

NEIPA
Target Mash PH per BrunWater with salt adjustments: 5.2
Water to Grist L/Kg 2.6

STOUT
Target Mash PH per BrunWater with salt adjustments: 5.18
After 6.9 gr of baking soda to up the Ph
Water to Grist L/Kg 3.1

 

[Minbari]

does that application take the grain into account when deciding what the Ph is?

where did you get the numbers for the water report profile?

you mentioned that you take the readings durring the boil. any reason for that? you want to know what your PH is durring mashing, so that the alpha and beta enzymes can do thier job most efficiently. what the PH is durring boil really isnt important. hops are gonna effect PH as they are isomerized as well

 

[ALD]

Responses in blue

does that application take the grain into account when deciding what the Ph is? Yes

where did you get the numbers for the water report profile? The kit from More Beer + the city water profile
you mentioned that you take the readings durring the boil. You misunderstood me, the samples are taken during the mash. I don't get to read them until during the boil because I am waiting for them to cool down. I am not trying to make adjustments during the mash - from what I've read Ph is most crucial in the first 20-30 mins, but readings shouldn't be taken until minute 20th, that leaves almost no room to maneuver. My goal is to forecast as accurately as possible. any reason for that? you want to know what your PH is durring mashing, so that the alpha and beta enzymes can do thier job most efficiently. what the PH is durring boil really isnt important. hops are gonna effect PH as they are isomerized as well

 

[Minbari]

Responses in blue

that is correct. you want to make changes to it fairly soon in the mash. if you wait until the boil, then you dont need to measure it. there is nothing to be done at that point.
your mashes are too acidic if those measuments are right. I am assuming you are cleaning the measurement vessel between samples. (clear water)

you dont have to let it cool. its only gonna be 150F and those meters are temp compensating.

 

[Sandy Feet]

Stupid question:
Are you only concerned with PH because of your gravity?
If so, why not try a recipe with regular, spring water and see what happens?
I don't measure it at all with 5-gallon batches. I like my beer, know my efficiency sucks, and add grain to make up for it. If I were doing it commercially and trying to save money, yes, I would check everything. At this level, relax and have a homebrew. It is a hobby.

 

[Donoroto]

Ok, so let's assume your pH meter is accurate.

Low pH can be from the malt, the added salts/acids, or the water. Note that water has little effect, and the additions are likely easily calculated... leaving the grain. Which might not be consistent with the brunwater assumptions.

I'd try a different program instead of brunwater, maybe the recipe tool here? And see what that says. Maybe that's the issue?

 

[HighVoltageMan!]

That is an extremely low pH. Your water is very low in alkalinity, but I suspect it's a measurement problem. To hit 4.0 pH in a mash is lower then most finished beers. Is the pH probe calibrated? Do you add anything other than brewing salts? What temperature do you measure at?

The pH should be measured at room temperature and it will be @ .2 lower at mash temperatures compared to room temperatures.

I find that the mash pH will be fairly stable at 5-10 minutes. There are a lot of people who claim otherwise, but that has been my experience. The difference in pH from 10 minute to 60 minutes is no more than .1 pH, usually lower.

 

[ALD]

That is an extremely low pH. Your water is very low in alkalinity, but I suspect it's a measurement problem. To hit 4.0 pH in a mash is lower then most finished beers. Is the pH probe calibrated? Do you add anything other than brewing salts? What temperature do you measure at?

The pH should be measured at room temperature and it will be @ .2 lower at mash temperatures compared to room temperatures.

I find that the mash pH will be fairly stable at 5-10 minutes. There are a lot of people who claim otherwise, but that has been my experience. The difference in pH from 10 minute to 60 minutes is no more than .1 pH, usually lower.

This is the kind of response I was hoping for. The jumping around in pH measures is what is throwing me off, I don't know if that is normal. If I understand you correctly, you expect pH to be relatively stable during the mash, whether it is on target, too low, or too high, you expect it to oscillate by let's say +-0.2? Is that what in general should be expected / others think?

If so, I stop worrying first about the actual value and I now know that either there is an issue with the measuring tool or the time the sample is sitting idle, because as you can see, it is jumping all over the place. By the time the samples are read, I don't expect them all to be at the exact same room temp (~25C here), but I wouldn't think that +- 2 C variance would not cause such disparate readings.

 

[The Brew Mentor]

I'd start by trying to verify things.
Calibrate your pH meter, then check your water pH. Then add a measured amount of acid to the water to make sure that those mixed hit the target pH. It's possible that the acid you're using may be an incorrect %.
Then starting with you brewing water adjusted you can add salts and grains for a very predictable drop into the pH range you're targeting.
Trying to mix it all together, measuring and adjusting on the fly is pretty much impossible to do and be even close to target.
The advanced water calculator on BF works great and at minimum, I'd load it and compare to what you're using.
Good luck and let us know the results.
Cheers
Brian

 

[The Brew Mentor]

Oh and another thing, the temperature adjustment on pH meter is fine, but using a hot sample isn't a great idea for the life of the meter.
You only need about a teaspoon of wort for the reading. If that's put into anything cool, it'll drop temperature immediately. That way you're not waiting.
For me, a teaspoon or so pulled and put into a cold coffee cup works great. The sample is immediately cooled and ready to read. No waiting.
Cheers

 

[HighVoltageMan!]

you expect it to oscillate by let's say +-0.2?

Yes, that would be the most.

but using a hot sample isn't a great idea for the life of the meter.

Exactly. I was trying to say that in the earlier post, but it didn't come across as clear. The sample should always be read at room temperature, the pH at room temp will be .2-.3 points higher than the pH at mash temp. pH is affected by temperature.

A good meter that is calibrated should show relatively stable pH during the mash, usually moving down slightly with time. Typically the pH of the collected wort after mash will rise during the sparge and can be adjusted with acid.

 

[The Brew Mentor]

Yes, that would be the most.

Exactly. I was trying to say that in the earlier post, but it didn't come across as clear. The sample should always be read at room temperature, the pH at room temp will be .2-.3 points higher than the pH at mash temp. pH is affected by temperature.

A good meter that is calibrated should show relatively stable pH during the mash, usually moving down slightly with time. Typically the pH of the collected wort after mash will rise during the sparge and can be adjusted with acid.

That is unless the sparge water is adjusted and then the pH remains almost exactly the same.