Help, keeping getting wrong mash ph

[aarong]

I have been having issues hitting my correct mash ph. This is in beer smith and Brun water.

It might be to how I am entering my water profile

I am blessed to have a detailed water report for my area

My water report gives the following

Total Hardness (as CaCO3) 102 mg/l or 5.92 GPG
Total Alkalinity(CaCO3) 80
Carbonate alkalinity(CaCO3) 0
Bi-Carbonate Alkalinity(CACO3) 80
Non carbonate Hardness( CACO3) 22

Full report on page 4(http://www.ycua.org/GLWALabReports/2016-06 Minerals.pdf)

I am not sure what to enter in beer smith/brun water as bicarbonate.

The Alkalinity, effective hardness, and residual alkalinity vary and I'm not sure if I am adjusting to get it to match my water profile.

For example if I use a Bicarbonate in beer smith of 97ppm
Beer Smith Shows:
Alkalinity: 80ppm
Effective hardness: 26ppm
RA: 53 ppm

Does this match my water profile?

Thanks!

Aaron

 

[ajdelange]

What we are really concerned about is alkalinity but the less sophisticated programs use bicarbonate as a proxy for that because most of the alkalinity we find in potable water is caused by bicarbonate if the pH is in its nominal range. In that case bicarbonate is 61*alkalinity/50 so your alkalinity of 1.6 mEq/L corresponds to 97.6 mg/L bicarbonate.

Effective hardness is the whole calcium plus half the magnesium hardness with both expressed in ppm as CaCO3. Without knowing how the total hardness is apportioned between Ca and Mg it is impossible to calculate effective hardness but effective hardness really isn't considered any more. To compute RA, another "don't care", one must also know the relative calcium and magnesium hardnesses.

 

[aarong]

My calcium and magnesium are 27 and 11ppm respectively. AJ do you have any recommended programs for mash PH?

 

[mabrungard]

How are you measuring pH?

 

[aarong]

Hi Martin,

I am using a calibrated Milwaukee PH meter. I'm a little particular with it so I calibrate the night before each brew day. For some reason I am getting 0.2 PH off. Its also varying by around 0.25 ph from brun water and beer smith mash ph(in the program). I always take my reading at 77F.

I'm trying to hone this in to get a correct PH at mash in. I realize that there is a large number of factors especially varying mash PH. Should I not worry if I'm off for the first 10 minutes of the batch, before I can correct it? My biggest concern is that I open the mashtun, stir and take a sample and when I have to adjust alot I lose some temperature in my cooler. (Should I sample from my valve on the bottom of the cooler to avoid the temp loss?)

Sorry for all the questions!

Aaron

 

[mongoose33]

You're .2 off?

I'm normally within about .1, which is good enough for government work most of the time.

Last saturday, I had a predicted PH of 5.4. Ended up at 5.08 and I don't know why. I may post details in the brew science forum, but .2 away isn't awful and horrible.

I had terrific conversion despite the low PH (OG of 1.069), and just checked gravity which is at 1.013. No off flavors, though I would have liked more malt presence.

 

[aarong]

Ok I wasn't sure how far off 0.2 was. It seemed significant but maybe not then... that is quite far off from 5.4 to 5.08 what software did you use?

 

[mongoose33]

Ok I wasn't sure how far off 0.2 was. It seemed significant but maybe not then... that is quite far off from 5.4 to 5.08 what software did you use?

EZwater. I've never been that far off. It usually predicts something higher than what I get, but typically about .1 higher or thereabouts. And the beer is great, so I'm not all that concerned about it.

But I have no idea what happened last Saturday. I started w/ RO water so there were no surprises from tap water. The only thing I can figure--and I don't know how much sense this makes--is I used 2-row malt from my LHBS, whereas everything else I've brewed has been using malt from RiteBrew.

Could a different malt make that much difference? Doesn't seem possible, but that's the only explanation I can see at this point.

 

[ajdelange]

I am using a calibrated Milwaukee PH meter. I'm a little particular with it so I calibrate the night before each brew day.

You should be calibrating just before you brew as meters start to drift immediately after calibration. With a relatively new meter the drift might be small enough that you don't have to worry about it but you must verify that this is the case and even if it is calibration just before use is always the best practice. Check https://www.homebrewtalk.com/showthread.php?t=302256 for tips on how to calibrate and use a pH meter and how to do a test of its stability.

For some reason I am getting 0.2 PH off. Its also varying by around 0.25 ph from brun water and beer smith mash ph(in the program). I always take my reading at 77F.

It is to be expected that you will get predictions off by that much as the programs do not know the parameters of the malts you are using but can only guess at them.

I'm trying to hone this in to get a correct PH at mash in. I realize that there is a large number of factors especially varying mash PH. Should I not worry if I'm off for the first 10 minutes of the batch, before I can correct it?

Mash pH can take up to half an hour to stabilize by which time it is really too late to make corrections. The best thing to do is determine the required acid for the desired mash pH using one of the programs and then make a test mash with a portion of the grist. Adjust the planned acid addition based on the results of the test mash.

My biggest concern is that I open the mashtun, stir and take a sample and when I have to adjust alot I lose some temperature in my cooler. (Should I sample from my valve on the bottom of the cooler to avoid the temp loss?)

You really want to give a quick stir before grabbing a sample to make sure that the liquid you take is representative of what is happening within the grist particles.

AJ do you have any recommended programs for mash PH?

All have limitations but any will do. You can certainly put together a more robust spreadsheet (i.e. one that does use the shortcuts and approximations that the popular ones do) but this adds complexity and the quality of the available malt models is such that tuning 0.01 pH by more accurate water chemistry will be swamped by an error 5 to 20 times that from the malt models. More accurate malt models also exist but they required detailed measurements of the actual malts and as those are only made by a few of us that information is not generally available to you.

 

[aarong]

This is awesome AJ thank you!

For the test mash do I just scale down the mash and find the acid additions needed and scale up the acid back to batch size? Does it scale up linear enough to work?

 

[ajdelange]

Yes, should be.