Bru'n Water v5.3 is producing lower pH predictions than past versions

[Horseflesh]

I'm moving to the new version, and when I put in a couple of old recipes I noticed that the mash pH predictions were lower. I have triple checked that I have copied over the water report values etc correctly. I know the calculations have changed, so I assume this is perfectly fine and normal... but wanted to discuss it.

For lighter beers, the new predictions are about 0.2 units lower than before.

For a darker beer, the new prediction is about 0.1 unit lower than before.

If anything, I find my mash pH to be a tenth or two higher than the predictions, so this increases the gap I deal with. What is the best way to improve the predictions? (It may be when I draw my sample too, I dunno.)

 

[ajdelange]

The discussion will be the same old tired one. There are two parts to the problem: accurate malt models and proper algorithms for processing them. Malt models are a perennial problem but the algorithm problem solution exists and is known. But authors of spreadsheets don't adopt them for various reasons that I can only guess. Until they do you will have to contend with both types of errors. All I can suggest is get a better spreadsheet.

 

[mabrungard]

For lighter beers, the new predictions are about 0.2 units lower than before.

For a darker beer, the new prediction is about 0.1 unit lower than before.

Thanks for the info. May I ask what your water source is and its quality? Is it consistent? How are you measuring pH and verifying that the instrument is accurate? How thick or thin is your water/grist ratio?

 

[Horseflesh]

Happy to help! LMK if you want me to send copies of any source documents.

My water source is Seattle-area local tap, which is very soft. I asked the water district and they said it is pretty consistent across the seasons, so I have lived with just one Ward Labs test.

This is how I have put the test results into BW, which as far as I can tell I have done correctly (Had to use the SO4-S conversion for example.)

https://i.imgur.com/IQGXcwg.png

I always add minerals appropriate to style, usually using the built-in presets like "Yellow Balanced."

My meter is a Hach Pocket Pro + which I calibrate on brew day before measuring my samples. Samples are drawn at 15 minutes into the mash.

I have only spot checked a few past brews in v5.3, but a good example is my recent brew of JZ's Czech pilsner. There was nothing funny going on like lots of mash steps, it was a straightforward brew day with 2 grains, 1 sacc rest and a mashout.

I set up v4.2 with a little phosphoric acid to hit a mash pH of 5.4. My actual result was 5.34, which I thought was great. (My typical error is a higher measured pH, no idea why this one was lower.)

I put the same grain bill, acid etc into v5.3, and it predicted pH of 5.21.

I am a no-sparge EBIAB brewer, so the mash looked like this:

Grist weight 12.8 lb
Total water 9.68 gal
Ratio 3.04 qt/lb (most of my ~1.05ish brews are in this ballpark)

In the Grain Input screen, v4.2 and v5.2 agreed completely on the color predictions. Here's an image of that screen from v4.2: https://i.imgur.com/Sh5czVF.png

I did have the "Pilsen" mineral target set, but ignored those values in favor of Czech pils advice culled from various forum threads, which was basically "add a little calcium and don't worry about the rest of it." I only added CaCl2, and my ion values in the mash were calculated to be: Ca: 19.8 / Mg: 0 / Na: 8 / SO4: 3 / Cl: 30

The CaCl2 and acid were added before heating the water.

And lastly, here is a side by side shot of the Water Adjustment tab from each version. Everything should be identical except the pH prediction... but it's always possible I have made a mistake.

https://i.imgur.com/q4DC7jV.png

 

[Bzart]

Not to hijack your post, but I too am seeing differences in pH estimates compared from V4.2 to V5.4. Screenshots attached. I used all same water, grist, volumes, etc.. Between the 2 versions, I'm seeing a 0.3 difference in pH (barring adding any water additions). I'm just curious if the changes in the versions lead to that much of a difference in estimated pH values???

V4.2: https://i.imgur.com/VJLJBvr.png pH est: 5.48
V5.4: https://i.imgur.com/spVxQzw.png pH est: 5.18

 

[Horseflesh]

Doesn't sound like a hijack to me!

 

[sixhotdogneck]

Be cautious with any and all of these types of spreadsheets. The algorithms and models used to estimate pH are not 100% reliable. pH varies over the course of the mash. The measure of actual mash pH at a certain time and the software prediction may be close by chance but don't necessarily have good solid mathematical/statistical correlation.

 

[Horseflesh]

I don't want to re-litigate the nature of these tools. I know they are not perfect. This is a discussion of a specific change in a specific tool.

 

[MerlinWerks]

I have noticed the same trend with lower predicted pH than the previous version and I do full volume BIAB as well. One of the listed improvements for this version is, "calculations for thin mashes are improved" so I'm guessing it has something to do with this.

 

[FunkedOut]

@mabrungard i haven’t received an email with the new version yet. Do I need to ask you for it somehow someway? thanks.

 

[Bzart]

@mabrungard i haven’t received an email with the new version yet. Do I need to ask you for it somehow someway? thanks.

I just got mine a few days ago, so I assume he's still in the process of sending V5.4 out.

 

[HausBrauerei_Harvey]

I just got version 5.3 and compared my mash pH for a moose drool style brew I worked up yesterday on the old version. new version 5.43 old version 5.45, which is pretty much the same in my book. My mash thickness is at 1.72 Qt/pound. my water is quite soft this time of year.

 

[mabrungard]

Yes Horseflesh, I'm not surprised that you are brewing with a thin mash and seeing quite a difference in pH prediction. Those brewing with more typical mashing water/grist ratio in the 1.5 qt/lb range should see little change between the new and old software version.

 

[schematix]

I recently did a pils with RO water and something similar to a yellow balanced profile. Full volume 3qt/lb.

The new BW predicted 5.35 and my actual was 5.65. Quite a miss. Usually I end up low and never high.

Sample taken 20 minutes in. MW102 freshly calibrated in 4 and 7 buffers.

 

[Horseflesh]

Yes Horseflesh, I'm not surprised that you are brewing with a thin mash and seeing quite a difference in pH prediction. Those brewing with more typical mashing water/grist ratio in the 1.5 qt/lb range should see little change between the new and old software version.

What would be the best way to improve predictions? Do I just need to apply a fudge factor?

 

[mabrungard]

What would be the best way to improve predictions? Do I just need to apply a fudge factor?

No, I need to figure it out better on my end. Sorry for the troubles. I need reports from brewers who employ really thin mashes (like BIAB brewers).

 

[Horseflesh]

Cool, I look forward to updates.

Let me know if you want my spreadsheet, so you can see the test recipes etc.

 

[ajdelange]

What would be the best way to improve predictions? Do I just need to apply a fudge factor?

The best way would be to understand the way in which relatively acidic and basic substances interact when mixed and write spreadsheets that reflect that basic chemistry. It is actually quite a simple concept but not one that the spreadsheet authors seem to be able to grasp. A set of Excel functions that can be used to prepare such spreadsheets is available to anyone who wants them.

 

[Silver_Is_Money]

The "Thought experiment" thread discusses this in some detail:

https://www.homebrewtalk.com/forum/...alidity-of-available-mash-ph-software.652095/

 

[schematix]

did any of the spreadsheets end up implementing AJs method?

I used RPIScotty's spreadsheet with the solver implementation and it was just as far off as BW. I also trialed that sheet with my last 4 brews and they were not even in the ballpark. Old BW sheets had closer predictions.

 

[FunkedOut]

No, I need to figure it out better on my end. Sorry for the troubles. I need reports from brewers who employ really thin mashes (like BIAB brewers).

I received 5.4 about a week ago, but just got around to kicking the tires tonight. Thanks, Martin!

I have some feedback for you from my last two brews.
Both brews were planned to be no sparge, full volume mashes, for 90 minute boils.
That's ~9.5 gallons for ~10 lbs of grain.
I ran out of space in the mash tun for both brews.
Right about a gallon of mash water, along with minerals and acids, we left out of each mash.
Not perfect data, I know, but here goes:

Mexican Lager
4.2 prediction = 5.40
5.4 prediction = 5.12
actual pH = 5.48

Vienna Lager
4.2 prediction = 5.40
5.4 prediction = 5.15
actual pH = 5.19

If the last gallon would have fit, the pH would have been driven lower, due to the dissolved minerals and acid.

 

[Silver_Is_Money]

@FunkedOut, what were the primary base malts for each of these lagers, and what percent of the ~10 lb. grist did they represent? Were any caramel/crystal malts involved? Munich? Vienna? .... My first presumption is that the base malt for the Mexican Lager had a much higher DI_pH (I.E., is much more basic with respect to 5.4 pH) than the base malt for the Vienna Lager. And I presume that BW assigns the same relative acidity (or caustic) value to all base malts, moderated only perhaps slightly by the Lovibond color. But base malts of highly varying acidity values generally hover about the very same color range, and therefore color alone does not properly indicate their relative acidity with respect to the chosen mash pH target.

Off topic, but how many quarts does your mash tun hold? I'm contemplating the switch to no sparge, and I use a 52 Qt. Coleman Xtreme cooler. I've been wondering how much grain and water I can safely attempt to get into it for full volume mashes. I doubt that my cooler actually holds 52 full Qts. safely (if at all). My first guess is that I can safely get a total of ~44 quarts of combined grist and mash water into it and still get the lid on.

 

[mabrungard]

Mexican Lager
4.2 prediction = 5.40
5.4 prediction = 5.12
actual pH = 5.48

Vienna Lager
4.2 prediction = 5.40
5.4 prediction = 5.15
actual pH = 5.19

Oh wow. I don't even know how to respond since the deviations are in opposite directions. Were all the minerals and acids added to the water prior to adding the grain?

 

[ScrewyBrewer]

Both brews were planned to be no sparge, full volume mashes, for 90 minute boils.
That's ~9.5 gallons for ~10 lbs of grain.
I ran out of space in the mash tun for both brews.
Right about a gallon of mash water, along with minerals and acids, we left out of each mash.
Not perfect data, I know, but here goes:

Mexican Lager
4.2 prediction = 5.40
5.4 prediction = 5.12
actual pH = 5.48

Vienna Lager
4.2 prediction = 5.40
5.4 prediction = 5.15
actual pH = 5.19

I think posting the complete recipe would be helpful and your mash water mineral/acid additions. Based on what I see above in a 5-gallon mash tun you used a nearly 1 gallon to 1 pound grain mash thickness.

 

[FunkedOut]

Here are the recipes for the two mashes.
All of the minerals and acids were mixed in with the water prior to under letting the grain.
~1 gallon of water did not fit in the mash tun.
Mash tun holds 10 gallons (Ss Brewtech InfuSsion Mash Tun). Actually holds about 10.67 gal.
Actual pH measurements taken with a freshly (minutes prior) calibrated MW102.
20 minutes into the mash, I drew about 5 gallons of wort off the bottom and poured back on top of the mash. Then drew the sample to measure pH.

Mexican Lager
8 lbs Weyermann Pilsner (2.0 SRM)
1.5 lbs Briess Flaked Corn (1.3 SRM)
7.5 oz Briess Victory (28.0 SRM)
=======================
9.96875 lbs total grist

4.84 g Calcium Sulfate
1.98 g Magnesium Chloride
1.87 g Calcium Chloride (99%)
0.46 g Sodium Chloride

3.79 g Lactic Acid (88%)

36.83 qts of Distilled Water
(3.694 qt/lb)


Vienna Lager
5 lbs Weyermann Vienna (3.4 SRM)
2.5 lbs Weyermann Munich II (8.9 SRM)
2.5 lbs Weyermann Pilsner (2.0 SRM)
0.5 lbs Wyermann Caraamber (27.0 SRM)
2.0 oz Wyermann Carafa Special II (434.1 SRM)
==============================
10.625 lbs total grist

3.91 g Calcium Sulfate
1.51 g Calcium Chloride (99%)
0.92 g Sodium Chloride

3.35 g Lactic Acid (88%)

37.14 qts of Distilled Water
(3.496 qt/lb)

 

[FunkedOut]

Oh wow. I don't even know how to respond since the deviations are in opposite directions.

I know. Head scratching.
I want to say this about the Vienna Lager...

In BeerSmith, this recipe calculates to 10.8 SRM (finished beer).
This wort came out crazy dark! I'd take my super-calibrated eye, have a few drinks and call it 25ish SRM.
Let me see if I can find a pic...

 

[ajdelange]

I need reports from brewers who employ really thin mashes (like BIAB brewers).

I don't think that's going to help much. You need to understand the chemistry well enough to appreciate that water volume doesn't have that much influence on the pH of a mash especially when residual alkalinity is low. You need to update your algorithm with one that is based on that chemistry. But consider water with alkalinity of 2 mEq/L. Malts have buffering of -30 to -60 mEq/Kg pH. To keep the math simple lets say that mashing is typically done with 2 L of water per kg of malt and that mash buffering is about the same as malt buffering or at least in the same range. Now lets double the mash water. With water at 2 mEq/L we have now increased the alkalinity by 2*2 = 4 mEq/kg malt. 4/30 = .133. 4/60 = 0.067. Thus we would expect doubling the qts/lb to have an effect of increasing mash pH by about 0.1. It's a little (but very little) more involved than this but it is very straight forward from the math. Looking for additional fudge factors to fit the experiences of BIAB brewers is not probably going to get you there.

 

[Silver_Is_Money]

One might initially presume that the various malts have the following 'ballpark' DI water mash pH's:

German Pilsner: 5.83 pH (80.3%)
Flaked Corn: 6.20 pH (15%)
Victory: 5.19 pH (4.7%)

Vienna: 5.63 pH (47.1%)
Munich: 5.52 pH (23.5%)
German Pilsner: 5.83 pH (23.5%)
Caraamber: 4.98 pH (4.7%)
Carafa Spcl. II: 4.66 pH (1.2%)

From the grist components 'presumed' DI or distilled water mash pH's and weight ratios it should be obvious that the Vienna lager should be expected to mash at an appreciably lower pH than the Mexican lager.

 

[mrstevenund]

I do BIAB and just got a PH meter. In a Saison I did see a jump between my new and old versions, but i didn't take a PH of the beer when I brewed. I'm getting ready to brew an Imperial Porter - 19lbs grain total, 1 lb black and .5 lb chocolate. I'll post results tonight when I brew.