Mash pH way low.. Where did I go wrong?

[LSUGrad00]

Ive been using Bru'n Water to calculate my salts and mash pH for a year or so now, but only recently purchase a pH meter. Yesterday was the second brew I've tested the mash pH on and both have been substantially low (-.4 and -.6)

I don't think this is a software issue because three different water spreadsheets all gave me a target of 5.4 +- .1, but the measured value was 4.8. :smack:

I calibrated the pH meter and brought the sample to room temp before taking the readings and then re-calibrated after the pH was so far off expected value. Oh and I'm using 100% RO water (7 ppm & 6.5 pH) and building up from there.

I'm at a loss on where to start with tracking down the issues... Anyone have a suggestion?

Thanks!

 

[hunter_le five]

What kind of pH meter?

A lot of the cheaper ones are wildly inaccurate.

 

[McKnuckle]

Perhaps a dumb question, but: How good were the beers you brewed using just the calculated pH estimates? How close is your predicted efficiency vs. actual?

If the beers are good and you're hitting the expected gravities, the only real problem you have now is that you bothered to actually measure. Sometimes science actually does get in the way...

(And P.S., I am definitely not a science Neanderthal. I just think that sensory results usually trump numeric data in terms of what matters.)

 

[frettfreak]

Couple things. First i would make sure you are calibrating the meter correctly. the other issue could be a faulty meter, or your "RO" water. If you are getting it from a machine, i would be careful. If you meter has the ability to check PPM of the water, check it. RO should be close to zero ppm. However, i bought RO water from one of those dispensers once.... its was over 450ppm!!!!! the problem there would be whats making up your PPM in the RO water. I know those machines are supposed to be serviced and filters replaced VERY regularly but that doesnt mean it happens like it should.

The other would be to post your recipe, and water additions that way we could verify what you are doing is accurate.

I know the Bru'n Water spread sheet has been fairly close for me, but i always hold of on to 50% of my lactic acid additions til AFTER i check my mash PH and adjust if i need it from there. The reason i did this is because i would constantly get lower mash ph by just going off the spreadsheet (though its more likely that the issue was the composition of my water because my water co. pulls from multiple sources and it changes throughout the year)

 

[rhys333]

Ive been using Bru'n Water to calculate my salts and mash pH for a year or so now, but only recently purchase a pH meter. Yesterday was the second brew I've tested the mash pH on and both have been substantially low (-.4 and -.6)

I don't think this is a software issue because three different water spreadsheets all gave me a target of 5.4 +- .1, but the measured value was 4.8. :smack:

I calibrated the pH meter and brought the sample to room temp before taking the readings and then re-calibrated after the pH was so far off expected value. Oh and I'm using 100% RO water (7 ppm & 6.5 pH) and building up from there.

I'm at a loss on where to start with tracking down the issues... Anyone have a suggestion?

Thanks!

Can you post your grain bill and mineral additions? Also, what were the programs you compared with?

 

[LSUGrad00]

What kind of pH meter?

A lot of the cheaper ones are wildly inaccurate.

This one Omega PHH-7011.

Perhaps a dumb question, but: How good were the beers you brewed using just the calculated pH estimates? How close is your predicted efficiency vs. actual?

Beer is good, not great, but we always strive for better don't we. Efficiency is typically in the low to mid 70s.

First i would make sure you are calibrating the meter correctly. the other issue could be a faulty meter, or your "RO" water.

I calibrated twice following the directions that came with the meter. I have an RO water system at home the total disolved solids were 7ppm and the pH was down from 8.8 at the source to 6.5.

Can you post your grain bill and mineral additions?

Bru'n Water (5.37) , EZ Water Calculator (5.58), and Brewer's Friend (5.56)

Grain Bill
Briess 2-row - base malt - 16lbs - 1.8L
Carapils - Crystal malt - 11oz - 1.5L
Carastan - Crystal malt - 4oz - 40L

Water Profile
100% RO

Water Additions
6G mash
6G sparge, Batch size is 7G

Minerals
Gypsum 1g/gal
Calcium Chloride .75g/gal
Epsom Salt .4 g/gal

Estimated Mash pH = 5.37


ETA: Thanks for all the help guys, I'm sure I'm missing something obvious.

 

[frettfreak]

This one Omega PHH-7011.



Beer is good, not great, but we always strive for better don't we. Efficiency is typically in the low to mid 70s.



I calibrated twice following the directions that came with the meter. I have an RO water system at home the total disolved solids were 7ppm and the pH was down from 8.8 at the source to 6.5.



Bru'n Water (5.37) , EZ Water Calculator (5.58), and Brewer's Friend (5.56)

Grain Bill
Briess 2-row - base malt - 16lbs - 1.8L
Carapils - Crystal malt - 11oz - 1.5L
Carastan - Crystal malt - 4oz - 40L

Water Profile
100% RO

Water Additions
6G mash
6G sparge, Batch size is 7G

Minerals
Gypsum 1g/gal
Calcium Chloride .75g/gal
Epsom Salt .4 g/gal

Estimated Mash pH = 5.37


ETA: Thanks for all the help guys, I'm sure I'm missing something obvious.

Man... I am at a loss here as well. Brun'water shows me 5.35.

The one thing i notice in there is that your sulphate and chloride are really high, but i am pretty sure the spread sheet should account for all that and honestly not sure what effect (if any) this is going to have on PH that isnt accounted for.

you didnt use any acid malt or lactic acid correct? so your "actual" PH was 4.7 or 4.6?

Maybe one of the water masters around here can chime in and set us all straight cause i am stumped.

Do you have PH strips? Maybe test with the strips and the meter and see if maybe the meter is just borked? Strips arent super accurate but should give you a decent idea if your meter is at least in the ballpark.

Was just reading through the manual for that meter, what is the slope your meter is displaying?

 

[Gavin C]

Assuming the grain weights and water volumes are all correct I can't see how the true mash pH would end up this low.

We can make one of two assumptions.
1: The data is correct and the mash pH has inexplicably gone this low
2: The data is incorrect.

Reading the thread it appears only assumption 2: holds any validity.

This leads us to a number of possibilities
1: The meter is solid but is calibrated incorrectly
2: The mash sample was taken much too early on n the mash (20-30 mins of mash time is needed to get a good representative sample)
3: Calibration and sample collection are good but the meter's stability is off.

To look at these:
1: How do you calibrate, I'm assuming a 2 point calibration
2: When did you take the sample for mash pH reading
3: Perform a stability check as outlined in the pH meter sticky in the brew science forum.


Hope I don't steer you off target but this is my clumsy train of thought on your problem.

 

[coyotebrew]

I was wondering something about this exact conundrum #2 as stated by gavin and now i have my answer 20-30 minutes into the mash to take the ph reading! Im guessing that might be the OP issue but im no expert just a guy who likes beer!!!! Peace out

 

[frettfreak]

I was wondering something about this exact conundrum #2 as stated by gavin and now i have my answer 20-30 minutes into the mash to take the ph reading! Im guessing that might be the OP issue but im no expert just a guy who likes beer!!!! Peace out

I will preface this with saying i have only been testing my PH for 20- 30 brews so i am still relatively new at it. However, I have taken samples of the same wort anywhere from 10-30 min and dont usually notice any change. Even at 5 min do i rarely see it change. as long as i gave it a good thorough mash in, then stir again really well right before i take the sample. I also run off a few cups before taking my sample as well just to make sure i am getting a good reading.

I am just relaying my personal experiences though, not saying that is right or wrong, just how i have done it and my results. :fro:

 

[stat]

I don't know about Briess but when I use Rahr pale malt my pH is normally .3 lower than all the calculators expect.

 

[Gavin C]

I will preface this with saying i have only been testing my PH for 20- 30 brews so i am still relatively new at it. However, I have taken samples of the same wort anywhere from 10-30 min and dont usually notice any change. Even at 5 min do i rarely see it change. as long as i gave it a good thorough mash in, then stir again really well right before i take the sample. I also run off a few cups before taking my sample as well just to make sure i am getting a good reading.

I am just relaying my personal experiences though, not saying that is right or wrong, just how i have done it and my results. :fro:

I would agree with you. I don't believe sampling too early to be the sole cause of the problem but could be contributing to too low a reading if other errors are in play.

I think the calibration or meter stability are the two likeliest possibilities.
I mentioned sampling too early just to be thorough, covering all possible contributing bases.

I do believe it's measurement error in some form. I don't believe the mash pH could have gone that low assuming all weights, volumes and minerals are correct as stated by the OP. (I have no reason to doubt the OP)

 

[LSUGrad00]

I'm in agreement with Gavin. This has to be some sort of sampling/measurement error on my part.

The measures of grain/minerals/water should all be accurate. I measured all but the specialty grains myself. I don't keep those on hand so I source those from the local homebrew shop.

I've called a friend at a brewery in town and I'm going to run over there next time they brew and compare my meter to what they are getting.

I'm using a two point calibration and the slope on the meter is only 93%, but user error seems like the most obvious culprit.

 

[Gavin C]

Mix up some calibration solution and perform a stability check on the meter.

Keep sampling the same solution at various intervals recording pH and temperature each time.

But that is a great idea, if you can compare your values to another tried and true meter, run with it.

I think @Mcknuckle hit the nail on the head earlier in that the data itself shouldn't worry you if the beer's flavor, mouthfeel, head retention etc are all in line with your expectations. This really highlights a problem with the meter (most likely)or your process of sampling and/or measuring.

I use Bru'n water too and find it to be very accurate (within 0.1 of measured pH usually). The meter is very useful for finding this out and for tweaking planned acid adjustments based on passed brews.

My process is a little different to yours but I'm not using RO water (yet)

I've said it before and believe it to be true, no data is better than bad data with regard to pH readings.

BTW: Hope you get this minor kink in your brewery ironed out. Best of luck with it. Let us know how the meter stacks up to the commercial one and/or the stability check.

 

[SpeedYellow]

When the experts chime in, I'm sure they'll say that you couldn't possibly get to a pH 4.8 with that malt bill and no added acid. Sounds like measurement error.

 

[hunter_le five]

Who measured the grain bill? You, or the HBS?

 

[LSUGrad00]

quick update...

Ran by the local brewery today. We measured a sample with two of their pH meters, then measured with mine. The pH reading was the same on both of their meters, but my meter was .2 lower.

I ran through the calibration routine using the 4.0 and 7.0 solution that came with my meter, tested again, and got the same value. My meter was still .2 lower.

The brewer brought out their calibration solution. My meter read 6.8 in their 7.0 solution and 3.8 in the 4.0 solution. I recalibrated my meter using their calibration solution and my meter read within .01 of theirs.

How long does calibration solution typically last before going bad?

 

[SpeedYellow]

What calibration solution do you use? You'll find various complaints on Amazon about certain of them.

 

[LSUGrad00]

Whatever generic solution that came with the meter. I'll have to look around for some bigger bottles. These are 2oz at most.

Guys at the brewery dumped mine, washed out the containers, and refilled with their solution.

Nice guys, and it always when you bring a few homebrews to share.

 

[iijakii]

In addition to the pH meter focus, how about the scale? I have had a lot of issues using my various kitchen scales to weigh in grams -- even though they claim to be fine. Had to get one of those tiny ones for crack dealers. I wouldn't be surprised if you're using way to much gypsum etc.

Also, are you making sure your lovibond is correct on the grain? For instance Marris Otter is commonly found in the low 2s, 3, all the way up to 4.5L.

Might be a .1 difference from all of these things just adding up.

 

[Gavin C]

I got the little pillows of powder to make fresh solution with each time. At two brews a month the solutions will expire long before I would get through them. The powder pillows solve that problem.

+1 on the crack dealer scales for minerals and a solution of known concentration for CaCl2 additions. That keeps and can be added as a ml addition rather than g addition.

Next thing to do is definitely check the meters stability.

Sounds more and more like a compounding of errors inherent in the device

 

[TheAleRunner]

Nice guys, and it always when you bring a few homebrews to share.

I notice you said nothing of their beers.

I kid, I kid.

 

[ScrewyBrewer]

Are you storing your meter in the recommended storage solution between use and not allowing the bulb to go dry? For example I use HANNA HI70300 storage solution with an expiration date of 9/2019. Once the bulb drys out, or if not stored in storage solution that will lead to calibration errors and readings.

 

[LSUGrad00]

I notice you said nothing of their beers.

They are nice guys, but their beer... well they are nice guys

To follow up on this..

I finally got around to testing the meters stability yesterday.

I calibrated the meter and put the meter back in 4.0 pH buffer solution and watched the readings for about 10 minutes. The readings jumped up and down between 3.92 to 4.15.

Finally I got frustrated called Omega. After Navigating the phone tree from hell I eventually spoke to a tech that was great. I explained the problems I was having and everything I had tried. He walked through a few things with me, and decided that there was definitely a problem with the meter itself and that it wasn't a bad probe.

The tech took my address and sent out a new meter with overnight shipping. :rockin:

I got the new meter this morning and will check the stability on the new meter tonight.