Why is my mash ph always too low?

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

merlyone

Well-Known Member
Joined
Mar 7, 2022
Messages
62
Reaction score
16
Hi all, I’ve noticed that my mash ph is almost always under 5. Usually 4.3 (15min after mash in) and end of the mash 4.5.

Here’s the receipe:

Fermentables (6.69 kg)
3.613 kg - Pale Ale Golden Promise 3 EBC (54%)
1.338 kg - Oats, Flaked 2.8 EBC (20%)
670 g - Wheat Malt 4 EBC (10%)
530 g - Carapils 2.6 EBC (7.9%)
340 g - Naked Oat Malt 5 EBC (5.1%)
201 g - Maltodextrin 5.9 EBC (3%)


Hops (480 g)
15 min - 30 g - Fuggles - 4.5% (8 IBU)
Hop Stand
30 min hopstand @ 80 °C
30 min 80 °C - 100 g - Mosaic - 9.3% (16 IBU)
30 min 80 °C - 50 g - Citra - 12% (10 IBU)
Dry Hops
Day 4 - 100 g - Mosaic - 12.25%
4 days - 100 g - Citra - 13%
4 days - 100 g - Galaxy - 15.7%


Miscellaneous
Mash - 0.192 g - Baking Soda (NaHCO3)
Mash - 10.829 g - Calcium Chloride (CaCl2) 33%
Mash - 0.096 g - Chalk (CaCO3)
Mash - 6.9 g - Gypsum (CaSO4)
Mash - 5.271 ml - Lactic Acid 80%
Mash - 2.3 g - Magnesium Chloride (MgCl2)
Mash - 0.096 g - Slaked Lime (Ca(OH)2)
Sparge - 0.633 ml - Lactic Acid 80%
 
Usually I don’t use lactic acid at all and then the ph can be 5 or near that.

Thanks!
 
Do you have some information about your water source?

And isn't chalk and baking soda used to raise pH? Seems a bit to use both that and lactic acid at the same time? I'm no expert though!
And there is slaked lime too. If that mash is pH 5 without the lactic acid, there is something remarkable about the water, it would have to be either exceptionally high in calcium or very acidic. I'd first suspect the pH measurement.
 
Oh yeah, I should have mentioned I only use Gypsum and calsium chloride. Rarely lactic acid and chalc. That’s what the brewfather gives me. So I’m not sure is the problem in the water.

Here’s my source water.

Ca 15
Mg 1
Na 7
CI 6
So 27
Hco 42

Could it be something in the grain bill that reduces the PH?
 
Test strips or calibrated pH meter? Is sample allowed to cool to room temperature? Sorry to question the pH result, but these factors could lead you to a bad pH reading and have you chasing a ghost.

The additions below seem overly complicated, and in some cases are working against each other to control mash pH. What are you targeting for a water profile that requires all these additions? Your water looks like a small addition of gypsum and CaCl would get you to a great place for this hoppy ale. Get the Ca over 50 with a blend of gypsum and CaCl that gets S04 to about 100 and Ca to 50, I'd ignore the rest of the additions. Rerun your water calcs for the amount of Lactic Acid to hit a 5.4 mash pH and give it a try.
Mash - 0.192 g - Baking Soda (NaHCO3)
Mash - 10.829 g - Calcium Chloride (CaCl2) 33%
Mash - 0.096 g - Chalk (CaCO3)
Mash - 6.9 g - Gypsum (CaSO4)
Mash - 5.271 ml - Lactic Acid 80%
Mash - 2.3 g - Magnesium Chloride (MgCl2)
Mash - 0.096 g - Slaked Lime (Ca(OH)2)
Sparge - 0.633 ml - Lactic Acid 80%
 
Mash - 5.271 ml - Lactic Acid 80%
+1 on catalanotte's comments about simplifying your additions.
That looks like a boatload of lactic acid. My water is ~35ppm bicarbonate (close to yours) and I use 1-2ml in the mash for a 10 gallon batch. Skip the baking soda, chalk, and lime and greatly reduce the lactic acid and you should be much closer to your target.
 
Test strips or calibrated pH meter? Is sample allowed to cool to room temperature? Sorry to question the pH result, but these factors could lead you to a bad pH reading and have you chasing a ghost.

The additions below seem overly complicated, and in some cases are working against each other to control mash pH. What are you targeting for a water profile that requires all these additions? Your water looks like a small addition of gypsum and CaCl would get you to a great place for this hoppy ale. Get the Ca over 50 with a blend of gypsum and CaCl that gets S04 to about 100 and Ca to 50, I'd ignore the rest of the additions. Rerun your water calcs for the amount of Lactic Acid to hit a 5.4 mash pH and give it a try.


If you are not using lactic acid, then I find it hard to see how you mash pH is at 5, so it could be some sort of measurement issue.

Specifics on how you measure the pH can help to troubleshoot. (Instrument, calibration procedure, measurement temperature, etc.)

Also, you've given several recipes for mash additions. Can you give the grain bill, starting water composition, mash volume, and water additions with the specific measurements for each?
 
Test strips or calibrated pH meter? Is sample allowed to cool to room temperature? Sorry to question the pH result, but these factors could lead you to a bad pH reading and have you chasing a ghost.

The additions below seem overly complicated, and in some cases are working against each other to control mash pH. What are you targeting for a water profile that requires all these additions? Your water looks like a small addition of gypsum and CaCl would get you to a great place for this hoppy ale. Get the Ca over 50 with a blend of gypsum and CaCl that gets S04 to about 100 and Ca to 50, I'd ignore the rest of the additions. Rerun your water calcs for the amount of Lactic Acid to hit a 5.4 mash pH and give it a try.
I have a PH meter but now that you said it, i’t not calibrated att all! So that could cause the problem.

I have basic NEIPA profile that i’m targeting. Ca 110, mg 10, na 60, ci 150, so 150, hco 55.

I’ll try to calibrate the ph meter first and then let’s see if the problem still exists.
Thanks!
 
I have a PH meter but now that you said it, i’t not calibrated att all! So that could cause the problem.

I have basic NEIPA profile that i’m targeting. Ca 110, mg 10, na 60, ci 150, so 150, hco 55.

I’ll try to calibrate the ph meter first and then let’s see if the problem still exists.
Thanks!
I have found that I am better off using any one of the water/mash pH calculators and trusting the outcome. About every 5 brew days I will take the time to calibrate my pH meter and do a quality check. I have found that I am always within .05 of the expected so I don't routinely measure and chase mash pH on a brew day.

To get to that water profile above I would focus on the Chloride and Calcium above all else for a good hazy. You base water is pretty good for an IPA so I would not worry about adding Mg or Na and certainly would not try an increase the HCO which is only increasing your alkalinity and driving the need for higher acid additions. Unless you want an IPA with more perceived bitterness and less juicy NEIPA character I also suggest lowering the Sulfate to 50 to 75. I would only add CaCl and gypsum to get there. Many will debate the value of Sulfate to Chloride ratio but I do find it be a good guide when adding calcium to try and maintain balance for the style. A good NEIPA water should be between 1:2 and 1:3 with a max Chloride of about 200. This is based on reviewing a lot of recipes, discussion with brewers (home and pro), and some experimentation on my own batches.

Let us know how the next batch turns out.
 
I have found that I am better off using any one of the water/mash pH calculators and trusting the outcome. About every 5 brew days I will take the time to calibrate my pH meter and do a quality check. I have found that I am always within .05 of the expected so I don't routinely measure and chase mash pH on a brew day.

To get to that water profile above I would focus on the Chloride and Calcium above all else for a good hazy. You base water is pretty good for an IPA so I would not worry about adding Mg or Na and certainly would not try an increase the HCO which is only increasing your alkalinity and driving the need for higher acid additions. Unless you want an IPA with more perceived bitterness and less juicy NEIPA character I also suggest lowering the Sulfate to 50 to 75. I would only add CaCl and gypsum to get there. Many will debate the value of Sulfate to Chloride ratio but I do find it be a good guide when adding calcium to try and maintain balance for the style. A good NEIPA water should be between 1:2 and 1:3 with a max Chloride of about 200. This is based on reviewing a lot of recipes, discussion with brewers (home and pro), and some experimentation on my own batches.

Let us know how the next batch turns out.
Great thanks! So just to make sure, do you think I can leave them off like this?

Ca 110, MG 0, NA 0, CI 200, SO 60, HCO 0
 
Great thanks! So just to make sure, do you think I can leave them off like this?

Ca 110, MG 0, NA 0, CI 200, SO 60, HCO 0
I would not reduce the targets to zero, because you can’t reduce the minerals in you current water without RO dilution, and can never get to zero. Only chase Ca, Cl, and SO. The Mg, Na, and HCO are just fine as is, I am kind of jealous of how clean your source water looks. My well water has an HCO between 300-400 ppm :eek:
Here’s my source water.

Ca 15
Mg 1
Na 7
CI 6
So 27
Hco 42
I would build a target profile with he needed Ca, Cl, and So and let the rest be. Check out this water profile I threw together based on your source water and the suggested Ca, Cl, and So levels. Play with the additions to get where you want and watch the mash pH.
https://www.brewersfriend.com/mash-chemistry-and-brewing-water-calculator/?id=1H066KL
If you treat 10 gal of your source water with 4g of gypsum and 9 g of CaCl you should have a mash pH of 5.43 without any acid additions which is just fine for an IPA. I would add a small amount of lactic acid to your sparge (1 ml) to get the pH down as well. You can recreate this in the software of your choice, I am just used to using this one.

Happy brewing.
 
Agree with the posts that say the water additions seem overly complicated. It seems like they may be canceling each other out. Of course the goal is to get to the profile you want. But it's a worthy goal to try to get there with the least amount of additions...

I don't see your starting water ph listed? My water has a ph of 9, so it almost always needs some lactic acid unless it's a very dark beer. I also treat all of the water, to save time and effort. Depending on what the calculator says, that usually translates to 10 - 13 ml for 9 gallons of water. But it totally depends on the grain bill.

My question is does your calculator always miss the ph?

I use Brewer's Friend, and one thing I have consistently found is that is causes my mash ph to be too low by about 2 points. So, I adjust the calculation to shoot for a few points higher. If I set it for 5.5 target, I usually get 5.3 or so. But if I set it for 5.2 I am risking going under 5. The point is that after using the calculator for a while you can usually figure out how well it works and adjust.... At least that works for me.
 
Agree with the posts that say the water additions seem overly complicated. It seems like they may be canceling each other out. Of course the goal is to get to the profile you want. But it's a worthy goal to try to get there with the least amount of additions...

I don't see your starting water ph listed? My water has a ph of 9, so it almost always needs some lactic acid unless it's a very dark beer. I also treat all of the water, to save time and effort. Depending on what the calculator says, that usually translates to 10 - 13 ml for 9 gallons of water. But it totally depends on the grain bill.

My question is does your calculator always miss the ph?

I use Brewer's Friend, and one thing I have consistently found is that is causes my mash ph to be too low by about 2 points. So, I adjust the calculation to shoot for a few points higher. If I set it for 5.5 target, I usually get 5.3 or so. But if I set it for 5.2 I am risking going under 5. The point is that after using the calculator for a while you can usually figure out how well it works and adjust.... At least that works for me.

The pH of the water used in the mash doesn't really matter very much. The pH of low TDS water can change drastically with very small amounts of acid or base, none of which would have much effect on the mash pH.

Do mash pH calculators even ask for water pH? I don't think there's even a space for it on the one I use.
 
Do mash pH calculators even ask for water pH? I don't think there's even a space for it on the one I use.
Brewers friend uses source water pH in conjunction with the Alkalinity or Bicarbonate input to determine the carbonate ion concentration in ppm, as it can vary based on water pH. Pretty nominal impact but technically correct.
 
The pH of the water used in the mash doesn't really matter very much. The pH of low TDS water can change drastically with very small amounts of acid or base, none of which would have much effect on the mash pH.

Do mash pH calculators even ask for water pH? I don't think there's even a space for it on the one I use.

Brewer's Friend Water Calculator asks for the starting water ph. My understanding is the predicted mash ph is a factor of the starting water ph, the current dissolved "salts" in the water, the grain bill, and the "salt" additions. Hence the need for an online calculator!

I tried removing the starting water ph from Brewer's Friend and the predicted ph went from 5.3 up to 8.75! So at least for that calculator, the starting water ph is important.
 
Brewer's Friend Water Calculator asks for the starting water ph. My understanding is the predicted mash ph is a factor of the starting water ph, the current dissolved "salts" in the water, the grain bill, and the "salt" additions. Hence the need for an online calculator!

I tried removing the starting water ph from Brewer's Friend and the predicted ph went from 5.3 up to 8.75! So at least for that calculator, the starting water ph is important.

That is interesting. Does the predicted mash pH change much between starting values of 6 to 9?
 
I don't see your starting water ph listed? My water has a ph of 9, so it almost always needs some lactic acid unless it's a very dark beer. I also treat all of the water, to save time and effort. Depending on what the calculator says, that usually translates to 10 - 13 ml for 9 gallons of water. But it totally depends on the grain bill.

My question is does your calculator always miss the ph?
Looks like that way. Atleast it has been this way for a long time.

Source water’s ph is 8,5.
 
Starting water pH is essentially useless. Starting water buffering capacity is much more important. Your starting water has quite small amounts of ions/anions
Ca 15
Mg 1
Na 7
CI 6
So 27
Hco 42
BrewersFriend, Brew'nWater, MpH, MashMadeEasy, or any calc should be able to steer you in the direction you wish to go (110:200:60 Ca:Cl:SO4) without more than CaCl, Gypsum and acid or base, whichever is called for (I'd use baking soda if Ca is already good and Na doesn't get above 50-75 using it, or slaked lime if you can then redo Ca on the CaCl and Gypsum additions)
 
I would not reduce the targets to zero, because you can’t reduce the minerals in you current water without RO dilution, and can never get to zero. Only chase Ca, Cl, and SO. The Mg, Na, and HCO are just fine as is, I am kind of jealous of how clean your source water looks. My well water has an HCO between 300-400 ppm :eek:

I would build a target profile with he needed Ca, Cl, and So and let the rest be. Check out this water profile I threw together based on your source water and the suggested Ca, Cl, and So levels. Play with the additions to get where you want and watch the mash pH.
https://www.brewersfriend.com/mash-chemistry-and-brewing-water-calculator/?id=1H066KL
If you treat 10 gal of your source water with 4g of gypsum and 9 g of CaCl you should have a mash pH of 5.43 without any acid additions which is just fine for an IPA. I would add a small amount of lactic acid to your sparge (1 ml) to get the pH down as well. You can recreate this in the software of your choice, I am just used to using this one.

Happy brewing.
I put these amounts in brewfather and it gave me 21g (0,7oz) of calsium chloride and 2g of gypsum for 23L (6g) batch. Sounds pretty much to me…
 
The pH level could be due to warm
I’ll try to calibrate the ph meter first and then let’s see if the problem still exists.
Thanks!
Calibrate, but you also gotta measure pH of the wort at that calibrated level for best results. If you stick your pH meter in hot liquid, it'll show that it's far more acidic than it actually is.
 
That is interesting. Does the predicted mash pH change much between starting values of 6 to 9?

It changes a little, though not as much as I might have originally guessed. At starting water ph of 9 it's predicting 5.32, and when I put in a starting ph of 6 it's 5.3.

HOWEVER, I think you are correct that starting water ph does not matter that much. If don't enter anything, then ph is predicted to be 5.31.

When I got that 8.75 prediction I had entered 0 for the ph. That was a mistake I now realize - I was telling the calculator that I had very low ph water.

I don't understand it, but if I enter 0 - 4 the prediction is 8.75. A 5 it suddenly predicts 5.15, then slowly changes the prediction from starting ph 6 - 9, but not much. It doesn't really change again until the starting water ph is 12, then the prediction drops below 5.

I am guessing if you don't enter anything, the calculator must guess 5 for the starting water ph?
 
It changes a little, though not as much as I might have originally guessed. At starting water ph of 9 it's predicting 5.32, and when I put in a starting ph of 6 it's 5.3.

HOWEVER, I think you are correct that starting water ph does not matter that much. If don't enter anything, then ph is predicted to be 5.31.

When I got that 8.75 prediction I had entered 0 for the ph. That was a mistake I now realize - I was telling the calculator that I had very low ph water.

I don't understand it, but if I enter 0 - 4 the prediction is 8.75. A 5 it suddenly predicts 5.15, then slowly changes the prediction from starting ph 6 - 9, but not much. It doesn't really change again until the starting water ph is 12, then the prediction drops below 5.

I am guessing if you don't enter anything, the calculator must guess 5 for the starting water ph?

6 to 9 or so is the general range I'd expect water pH to be. If water pH 6 yields a prediction of 5.30 and 9 yields 5.32, then the 5.31 that you get for no entry is probably guessing something in between.
 
6 to 9 or so is the general range I'd expect water pH to be. If water pH 6 yields a prediction of 5.30 and 9 yields 5.32, then the 5.31 that you get for no entry is probably guessing something in between.

I think I'll keep entering the ph, but the learning (thanks!) is that the grain and salt additions are really what move the numbers. The calculator must have that 6 -9 range as part of how it works, but numbers outside of that range make it go a bit wonky. Otherwise I don't know how to explain that entering 3 or 4 for the starting water ph makes it predict 8.75 ph including the grain...
 
I chased my PH when I first started testing. I found the water source listed in Brewers Friend was a little out of date. Sent in a sample to Ward Labs and have been on track since.
Has anyone seen PH levels change with the seasons? Mine do some, but I think its due to my water source is from surface water.
 
Has anyone seen PH levels change with the seasons? Mine do some, but I think its due to my water source is from surface water.
It absolutely does change seasonally for a lot of places, absolutely. I am a chemistry analyst and have graphed it. Over several years I have seen a pattern of pH rising and falling every summer and winter, respectively, for my source water, which here is Lake Michigan. The difference here is small but noticeable, from 8.4 to 8.0. YMMV

1674821781891.png
 
My water comes from an 80 foot well and the composition of that can change from week to week. I have filled my hot tub and have had a cloudy water immediately, filled it the next time and it is perfectly clear but the bubbles when the pump run have a reddish look. Next time it is clear and the bubbles are now white.
 
Back
Top