Comparing Water Calculator Results - How to Proceed?

[Twang]

I've plugged in a couple upcoming recipes into BruN Water, EZ, MpH, and Brewers Friend.

American Wheat

• Wheat - 4.5lbs, 2.5L
• 2Row - 4.5lbs, 1.5L
• Munich - 0.5lbs, 6.5L
• Honey Malt - 0.25lbs, 22L

Water - 7 gallons Distilled

pH Results w/ no mineral or acid additions

• BruN - 5.7
• EZ - 5.83
• MpH - 5.85
• BF - 5.71

Mineral Additions

• Gypsum - 3.15g
• Epsom - 2.45g
• Salt - 0.35g
• CaCl - 2.1g

pH Results w/ mineral but no acid additions

• BruN - 5.56
• EZ - 5.76
• MpH - 5.73
• BF - 5.56

Acid
10% Phos - 21ml

pH Results w/ mineral and acid additions

• BruN - 5.41
• EZ - na
• MpH - 5.63
• BF - 5.4

I think the big discrepancy is how these handle Wheat. BruN and Brewers Friend are similar, and EZ and MpH are similar.
BruN and BF have the pH much lower than EZ and MpH w/ just the grain and water and no mineral or acid additions. Anyone know why this is?






American IIPA

• 2Row - 10lbs, 1.5L
• Munich - 1.0lbs, 10L
• CaraMunich - 0.25lbs, 50L

Water - 5.5 gallons Distilled

pH Results w/ no mineral or acid additions

• BruN - 5.67
• EZ - 5.66
• MpH - 5.69
• BF - 5.71

Mineral Additions

• Gypsum - 4.13g
• Epsom - 2.09g
• Salt - 0.55g
• CaCl - 1.49g

pH Results w/ mineral but no acid additions

• BruN - 5.49
• EZ - 5.59
• MpH - 5.53
• BF - 5.57

Acid
10% Phos - 10ml

pH Results w/ mineral and acid additions

• BruN - 5.4
• EZ - na
• MpH - 5.51
• BF - 5.51

BruN seems to lower the pH more than the others on all steps - grain, minerals, acid.



If my target pH is 5.4 should I go w/ BruN water and see what happens? Or does something seem off w/ the results?

 

[ajdelange]

I think the big discrepancy is how these handle Wheat. BruN and Brewers Friend are similar, and EZ and MpH are similar.
BruN and BF have the pH much lower than EZ and MpH w/ just the grain and water and no mineral or acid additions. Anyone know why this is?

First, the reason for the differences which it is important to understand. Caculation of mash pH is quite simple if you use the proper algorithm which none of these calculators do and one of the reasons for that is that they don't have the required information about the malts that they need. Of them, Brewer's friend comes closest to doing it right because he has gathered actual data on a rather large set of malts. Were he to refine (and repeat) all those measurements he'd be using the proper algorithm for the malts he measured. So lets say he did that. These would not be the malts you would be using because you'd buy your malts from a different maltster or even if from the same maltster from a different batch etc. So when it comes time for you to put your numbers in a spreadhsheet it has to WAG malt parameters from a list of types perhaps refined by color. It doesn't matter if the algorithm is perfect: GIGO. So all the spreadsheets are going to be wrong and, of course, you would like to know which is least wrong. That is an impossible question to answer as to do so would involve extensive experiments with thousands of brews.

American IIPA

• 2Row - 10lbs, 1.5L
• Munich - 1.0lbs, 10L
• CaraMunich - 0.25lbs, 50L

Water - 5.5 gallons Distilled

pH Results w/ no mineral or acid additions

• BruN - 5.67
• EZ - 5.66
• MpH - 5.69
• BF - 5.71

To these you can add
AJ - 5.64

Mineral Additions

• Gypsum - 4.13g
• Epsom - 2.09g
• Salt - 0.55g
• CaCl - 1.49g

pH Results w/ mineral but no acid additions

• BruN - 5.49
• EZ - 5.59
• MpH - 5.53
• BF - 5.57

AJ - 5.60

Acid
10% Phos - 10ml

pH Results w/ mineral and acid additions

• BruN - 5.4
• EZ - na
• MpH - 5.51
• BF - 5.51

A.J - 5.55

Yes, there is some discrepancy as each of the programs uses a different model for the malt's acidity/alkalinity. The AJ model is robust but the answers are not necessarily better than the other estimators as I too have to guess at what the malts you are using actually are like and do the calculations based on malts that I or Kai have measured which I am guessing are closest to the ones you are acutally using.

BruN seems to lower the pH more than the others on all steps - grain, minerals, acid.

That is an observation I have seen repeated here several times.

If my target pH is 5.4 should I go w/ BruN water and see what happens? Or does something seem off w/ the results?

The best thing to do is to make a test mash and measure its pH with a reliable pH meter. Absent that I'd go with the 10 mL phosphoric and assume that you will have a mash pH of about 5.55. If you really want pH 5.4 then the proton deficit of your base malt, as I modeled it (Weyermann pils) goes from 30 to 64 mEq and you will need about 35 mL more (total 47 ml -some extra for the Munich too) 10% phosphoric (1N) acid to get there.

 

[Twang]

A follow up:
Wheat pH 5.39
IIPA pH 5.41

BruN was spot on.

 

[ajdelange]

Keep checking with multiple calculators. It sometimes turns out that one gives better predictions than another for the particular style(s) you brew so that, as long as you stick to those, you can use that one with a fair amount of confidence. But when you move on to something different it is time to dust off the pH meter.

 

[dmr]

I've plugged in a couple upcoming recipes into BruN Water, EZ, MpH, and Brewers Friend.

American Wheat

• Wheat - 4.5lbs, 2.5L
• 2Row - 4.5lbs, 1.5L
• Munich - 0.5lbs, 6.5L
• Honey Malt - 0.25lbs, 22L

Water - 7 gallons Distilled

pH Results w/ no mineral or acid additions

• BruN - 5.7
• EZ - 5.83
• MpH - 5.85
• BF - 5.71

Mineral Additions

• Gypsum - 3.15g
• Epsom - 2.45g
• Salt - 0.35g
• CaCl - 2.1g

pH Results w/ mineral but no acid additions

• BruN - 5.56
• EZ - 5.76
• MpH - 5.73
• BF - 5.56

Acid
10% Phos - 21ml

pH Results w/ mineral and acid additions

• BruN - 5.41
• EZ - na
• MpH - 5.63
• BF - 5.4

I think the big discrepancy is how these handle Wheat. BruN and Brewers Friend are similar, and EZ and MpH are similar.
BruN and BF have the pH much lower than EZ and MpH w/ just the grain and water and no mineral or acid additions. Anyone know why this is?

You are indeed (at least partly) correct about the discrepancies as being due to how the different calculators handle wheat malt. Both MpH (my spreadsheet) and EZ Water predict wheat malt as having a higher distilled-water pH that typical pale (barley) malt. This aspect of these two spreadsheets is based on Kai Troester's published data for wheat-malt pH, which he measured to be 6.04.

With MpH you can go into the code and change the wheat-malt acidity value (currently -9.6) to change the wheat-malt distilled-water pH to whatever you think is the most accurate number (The default -9.6 yields the distilled-water wheat-malt pH of 6.04)

Both Brun Water and Brewer's Friend do not distinguish barley and wheat base malts, as one can only choose "base" for either type of malt.

As AJ often laments on this forum, it would be really great to have data on the distilled-water pH and buffering capacity of many more malts. The lack of wheat-malt data is just an example. With more extensive data one could (obviously) make more accurate predictions of mash pH using either AJ approach of directly counting protons or the other programs' rather more phenomenological approaches that use malt type and color to predict distilled-water pH and related data published by Kai Troester's to infer buffering capacity.

Cheers!