Why did my mash pH end up so low this time? Bru'n Water

Brewing Processes
1

Hello everyone!

Recently I brewed a German Pils… Grist comprised of 10# BestMalz Pilsen, 6oz Acid Malt and 3.5oz Melanoidin, for a 5-gal batch. OG was 1.047 (exactly where it was projected), preboil gravity right on as well.

I mashed in with 4.76gal of water, (1.75 qt/lb).

Using Bru’n Water, I targeted a mash pH of 5.25… So there was 2.5 mL/gal additions of phosphoric acid as well for the mash water, (10% strength).

My (starting) water looks like this:

Ca: 37
Mg: 10
Na: 15
HCO3: 128
Sulfate: 30
Chloride: 20
Akalinity (CaCO3): 105
Total Alkalinity: 86
Water pH: 6.5

I also diluted both mash and sparge water 50/50% with distilled for this beer, then added back a few brewing salts. So my “finished” mashing water profile was:

Ca: 63
Mg: 5
Na: 8
HCO3: 20
Sulfate: 100
Chloride: 25

My question is, my mash pH was lower than expected… Right around 5.1, if not a hair less. Typically, Bru’n Water is spot on with the estimates but this time it came out lower than targeted.

Is there something with the dilution of the mash water 50/50 I missed somehow in the program? I never been that far off with the pH before, usually no more than +/- maybe .05 (and not .15!). I did calibrate my pH meter before hand and allowed the sample to cool down to room temp before checking as I always do. All measurements of acid malt, acid additions and malt were accurate as they typically are (same scales / methods). I did acidify my (batch) sparge water as well to 6.0 using about 17ml of 10% acid as well.

Any idea to prevent this from occurring in the future?  Hopefully with this style it won’t affect the end result too much, but time shall tell!

Appreciate any information!

2

Best Pils is probably your culprit. Do you adjust for distilled water pH of the malt from the data sheet?

3

Yes, Best had a Pils malt lot that contained sauermalz last year.  I don’t recall the explanation, but you probably had some of it by accident.

4

Independent of the contamination, I believe Best is a bit more acidic than other Malts.

5

Target 5.2 and hit 5.1? Which ph meter? How old is your calibration fluid?

6

That would explain it I suppose! I ordered the malt in (20# from Farmhouse Brewing Supply) just a few weeks ago. My LHBS only carries Dingemans and Avangard Pils, wanted to try another one out for experimentation purposes. Next batch I will have to adjust accordingly now that I know this malt may be more acidic.

Klickitat,

I use the Milwaukee MW102 PH meter. Target was 5.25 (I usually target 5.2 to 5.3 for my IPA’s and lighter lagers, higher for stouts and such). Calibration fluid is only a few months old, kept cold in the fridge and the meter is calibrated with the fluid at room temp. I checked the probe back into the 4.01 reference fluid after my mash pH check and it was right on.

Big Monk,

What do you mean exactly? In the Bru’n Water spreadsheet, on the water adjustment sheet I do put 50% dilution of distilled water. I would assume this would adjust/balance the pH as needed for the mash. Do I need to adjust elsewhere for it? To be honest, I don’t typically use distilled water for dilution often, just this and a previous pilsner I did (which was 100% distilled). Cleveland water is quite neutral to work with, so it’s easy to get where I want to go for most styles. So perhaps I am a big ignorant using the spreadsheet properly for dilution!  :smiley:

So… Should I be concerned for mash pH just shy of 5.1 in a German Pils? I just assume it would be a bit more crisp if anything. I just hope it won’t be sour or something once fermentation is complete and it acidifies more. Time will tell I suppose!

7

Is your starting water made from scratch or domestic water supply? Alkalinity and mineral levels in water supplies can fluctuate.

8

No worries. Brun Water assumes that the distilled water mash pH (from the malt analysis data sheet) will be fairly close to the default of 5.75. So if the malt is more acidic, and you calculated 5.2, you would end up with a slightly more acidic mash pH

9

Your water could have changed.

10

That is possible, however, I just brewed an IPA just a week and a half prior that my mash pH was perfect as expected. In the past two years or so, my pH’s have been consistent with the same base water profile. It sounds like it was the malt, based on what others have noted and finding that topic discussing that particular pilsner malt and it’s acidity.

The city water is very consistent across multiple years and water tests for Cleveland I have found. They don’t change much at all. I assume it was malt driven vs. water.

11

I suspect, as noted earlier, that the issue is the Best Pils malt.
The bag I just finished using was routinely .1-.2 lower in the actual pH vs the predicted pH.
After the figuring it out, I just adjusted my water adjustments.

12

OP:  Been there.  Done that.  It will be just fine.  It may be a bit low for optimal conversion, but many lower their pH post mash and pre boil to this range, especially for a Pils.  You’re good.

13

Same here.  Though I experienced as much as 0.3 lower ph.  Going back to Weyermann pils.

14

Hard to beat Weyermann

15

Not to mention its(bests) ludicrous gelatinzation temp this year. No more best for me.

16

I can’t get Weyermann’s around here.
Anyone have experience with either:
Gambrinus or Franco Belges Pils malt?

17

I bet if you took a later pH reading from the mash (say closer to the end of your rest) that it probably crept up closer to 5.2. I have been noticing that with my mash pH’s. Sometimes you just can’t sweat it if your close enough, although I fully understand the need and desire to nail those numbers.

Cheers,

From one anal brewer to another.

18

Hey everyone! Just wanted to update my findings on my water pH issue…

So I brewed a cream ale following the pilsner I posted this about…  It, too, came up with a pH .15 lower than expected (about 5.15) with target of 5.3… Same exact spread. I double checked to make sure everything was filled out properly in Bru’n Water and it was.  Again, these two times have been the only time I have ever been off out of 20+ brews or so.

I did not use the same pilsner malt… The grist was comprised of Briess 2-row, Rahr 6-row and flaked corn dominantly with a little caramel and acid malt.  So there goes that theory!

Because it has been off, I decided to send my water to Ward for testing to confirm nothing has changed. I never did send my water out for testing before, instead, developed my Bru’n Water profile from various water analysis I found online around my area and averaged the data. The results came in yesterday and it appears my “estimate” was close, but not exact of course. Here is the report I got in:

pH – 7.6
TDS, ppm – 175
Cations/Anions, me/L – 2.9, 2.9

Sodium (Na) – 12
Potassium (K) – 2
Calcium (Ca) – 32
Magnesium (Mg) – 8
Total Hardness (CaCO3) – 113
Nitrate (NO3-N) – 0.1
Sulfate, (SO4-S) – 9
Chloride (Cl) – 17
Carbonate (CO3) - <1.0
BiCarbonate (HCO3) – 112
Total Alkalinity (CaCO3)  - 93
Total Phosphorus (P) – 0.55
Total Iron (Fe) - <0.01

Once I popped this new info in, my mash pH reduced on my pilsner sheet from 5.3 to 5.18… Practically right where I was per the actual pH reading.

So it appears it was my water after all and not the pils malt… So I am glad I had it checked to solve my issue once and for all. I plan to resend my water in mid-summer (June/July) to see how much it changes summer/winter.

Anyway, thanks for the help and input to troubleshoot this!

19

I have had similar issues which I chalked up to my acid malt being stronger than calculated on BW. Don’t know if acid malt does vary that much but adjusting it down corrected the problem (which would likely correct it regardless of the cause)