Wanted: Mash pH Measurements

[ScrewyBrewer]

I’m still hearing conflicting results though and that’s a problem for all of us. On one hand there’s reported evidence of mash pH values locking in quickly and remaining stable. On the other reports of mash pH rising throughout the entire mash.

I don’t think I’m misinterpreting what’s been posted here over the past day or two. How can those observations be accurate when they’re both completely different from each other?

 

[Paulaner]

I've also noted a slight PH rise during the mash of anywhere between .02 -.04. I also stick with the same water to grain ratio and perform a modified Brauwelt step mash and take the measurements at the completion of every step and cool the sample to the same temp of my calibration solution. Just talking out my a$$, but I wonder if this has something to do with our measuring process since we're not monitoring in-line readings.

 

[ScrewyBrewer]

I can live with a range of a few hundreds of a point but not a few tenths of a point of pH accuracy.

 

[Big Monk]

Short story: I am requesting that actual mash pH measurements (and relevant ancillary information) be posted in this thread.

Motivation: A number of recent threads on this forum have been discussing the relative merits of various programs that predict mash pH. However, in order to assess and develop such programs, actual data is required. So far, such data appears to markedly absent. Hence this thread. I hope in the long run this thread will be a useful repository of data for anyone interested in this subject.

What's needed: The following is needed for such data to be useful.

1. Grain bill [specific grains mashed and amount of each grain (in lbs), ideal if grain color (Lovibond) is also included)]
2. Amount of mash strike water (in gallons)
3. Ionic content of source water [Na, Ca, Mg, SO_4, Cl, Nitrate (if available) and alkalinity (as calcium carbonate or simply HCO_3 concentration), all in ppm (= mg/L)]
4. Salts added [CaCl, CaSO_4, MgSO_4, NaCl, NaHCO_3, and/or Ca(OH)_2, in grams]
5. Acids added [%'age and amount (in mL)]
6. Mash pH [when taken (from beginning of mash) and temperature of liquid when measured are helpful]


I'll get the ball rolling. Here are data from a recent beer of a fellow homebrewer:

5.0 Lbs Weyermann Pale Wheat
4.7 Lbs Briess American Brewer's Two-Row
0.85 Lbs Goldswaen Red (15L-23L caramel malt)
4 gallons distilled water
4 grams CaCl2
4 grams CaSO4
3.8 ml lactic acid (88%)
Mash pH 5.23 @ ~ 30 minutes

Cheers!

Entered this to check:

 

[ajdelange]

In my experience mash pH drifts dramatically in the first few minutes and then starts to approach an equilibrium value asymptotically with things pretty well settled at around 25 - 30 minutes. But additional "creep" of a couple of hundredths, up or down, from the 30 minute point on is possible. When I settled on 30 minutes as the point at which pH should be measured that was somewhat arbitrary but based mostly on the observation that things were pretty stable at that point and that, as the pH trajectory suggests, the reactions are pretty much, though not entirely, complete, at that point. IOW if beer produced with mash pH of 5.4 read at 30 minutes is good it doesn't much matter that the pH is 5.42 at 45 min or an hour. The 30 minute reading is a good and reasonable indicator. Plus you don't want to wait an hour to see if you screwed up. You don't want to wait half and hour so I recommend taking readings as quickly as you can for the first half hour and then more infrequently thereafter. With a little experience you will be able to predict where you will be at half an hour based on a couple earlier readings.

 

[Horseflesh]

Say we standardize on 30 minutes -- or any other value.

What if we do a step mash? Maybe I start with a 15 minute ferulic acid rest and then bring it up to the sacc rest temperature. Does the mash pH test timer start when the grain hits the water, or does it start at the beginning of the sacc rest?

 

[eric19312]

I’m still hearing conflicting results though and that’s a problem for all of us. On one hand there’s reported evidence of mash pH values locking in quickly and remaining stable. On the other reports of mash pH rising throughout the entire mash.

I don’t think I’m misinterpreting what’s been posted here over the past day or two. How can those observations be accurate when they’re both completely different from each other?

Would recirculation lead to faster stabilization of mash pH? Sounds like The Beerary clearly is recirculating (in line measurement) how about those hundreds of tests @mabrungard is reporting on? I have also seen effect where my early pH readings are pretty low (like 5.15 at 10 min when targeting 5.4 but they do seem to come up over time).

I'd also wonder if it would be different if you were using sour malt instead of lactic acid. Using lactic acid the acid is in the water and so the pH will start low and come up to final value as the grain neutralizes the acid in the water. Perhaps using sour malt the acid is released into the liquid at about the same rate as the neutralizing ions creating less of a transition.

I think building a data base like this is an interesting idea but wonder if differences in technique from brewer to brewer will hopelessly confound the results.

 

[ScrewyBrewer]

Well here's the thing. Are software developers supposed to include a disclaimer telling the user when their mash samples should be taken? In other words for example "This software's pH predictions should only be checked for accuracy 30 minutes into the mash with the temperature of the sample cooled to 77F/25C".

 

[ScrewyBrewer]

Would recirculation lead to faster stabilization of mash pH?

I use recirculation during the mash on my system so that's all I can speak to.

I think building a data base like this is an interesting idea but wonder if differences in technique from brewer to brewer will hopelessly confound the results.

Another great point. To add another twist what do users think when software displays a mash pH prediction? Using the same grain bill will one user think the pH prediction is valid at 30 minutes and another at 60 minutes? There are about a dozen bits of information that need to accompany any mash pH reporting in order to make it meaningful.

 

[dmr]

HCO3 . Bru'nWater reports alkalinity at 35 ppm.

I can see my post was a bit confusing. I did take a pH reading at the times stated above and after that I added more acid, amounting to the qty stated for each recipe. At the 60 minutes mark - end of mash - the pH was the one written above. So I would have to change my post and say that.

I know that the pH would rise during the mash, towards the end. My experience is that it's usually pretty stable and does not change all that much, unless you are adding heaping amounts of acid.

Thanks for the clarification. Cheers!

 

[dmr]

Entered this to check:

View attachment 609986

Nice! I cannot recall, have you made you calculator available?

 

[Big Monk]

Nice! I cannot recall, have you made you calculator available?

Yes. It’s at the site in my signature.

 

[eric19312]

This was a tricky one for the calculators. Nobody got it right. Bill was 90% base malt and 10% flaked wheat.

9.158 kg Pilsner Malt (Avangard) (1.7 SRM) 70%
2.616 kg Pale Ale (Dingemans) (3.3 SRM) 20%
1.308 kg Wheat, Flaked (1.6 SRM) 10%

Strike volume 38L
Sparge volume 50L

Base water (these are annual averages for 2018 for my location from water authority website)
Ca2+ 6.9
Mg2+ 1.14
Na+ 4.8
K+ 0.43
SO2- 0
Cl- 6.3
Alkalinity as CaCO3 25.08 (converted from Total Alkalinity)
NO3- 0.72

Salts added to mash water:
Gypsum 5 grams
Calcium Chloride 7 grams
Epsom 4 grams
NaCl 4 grams

Lactic Acid
Mash 9.5 mL
Sparge 1.5 mL

Tried multiple water calculators aiming for 5.4 mash, calculating for pH lactic acid requirements
Bru'n Water 2.5 mL
Brewers Friend 9 mL
Beersmith 10 mL
Water Engine 15 mL
I went with 9.5 mL based on the range

pH measurements - Apera meter, calibrated before brewing
10 min 5.08 at 17.1C
20 min 5.19 at 17.4C
30 min 5.22 at 18.4C and 15.4 Brix 1.061
75 min 5.26 at 17.2C and 19.0 Brix 1.076

For a rebrew I guess I'd go with 6mL lactic on this recipe

Final runnings pH 5.5

Kettle ph 5.35 at 18.1C and 10.1 Brix
Added 3mL lactic and brought kettle pH to 5.18

 

[Big Monk]

This was a tricky one for the calculators. Nobody got it right. Bill was 90% base malt and 10% flaked wheat.

9.158 kg Pilsner Malt (Avangard) (1.7 SRM) 70%
2.616 kg Pale Ale (Dingemans) (3.3 SRM) 20%
1.308 kg Wheat, Flaked (1.6 SRM) 10%

Strike volume 38L
Sparge volume 50L

Base water (these are annual averages for 2018 for my location from water authority website)
Ca2+ 6.9
Mg2+ 1.14
Na+ 4.8
K+ 0.43
SO2- 0
Cl- 6.3
Alkalinity as CaCO3 25.08 (converted from Total Alkalinity)
NO3- 0.72

Salts added to mash water:
Gypsum 5 grams
Calcium Chloride 7 grams
Epsom 4 grams
NaCl 4 grams

Lactic Acid
Mash 9.5 mL
Sparge 1.5 mL

Tried multiple water calculators aiming for 5.4 mash, calculating for pH lactic acid requirements
Bru'n Water 2.5 mL
Brewers Friend 9 mL
Beersmith 10 mL
Water Engine 15 mL
I went with 9.5 mL based on the range

pH measurements - Apera meter, calibrated before brewing
10 min 5.08 at 17.1C
20 min 5.19 at 17.4C
30 min 5.22 at 18.4C and 15.4 Brix 1.061
75 min 5.26 at 17.2C and 19.0 Brix 1.076

For a rebrew I guess I'd go with 6mL lactic on this recipe

Final runnings pH 5.5

Kettle ph 5.35 at 18.1C and 10.1 Brix
Added 3mL lactic and brought kettle pH to 5.18

I’ve got a few revisions to do on Monday. I’m going to cross check the background functions against A.J.’s latest release. Something seems fishy about that acid amount.

EDIT: I double checked and the calcs are correct. That is a considerable amount of grain that’s more basic than most. Still doesn’t explain the discrepancy but the amount seems less fishy now considering 13 ish kg of grain.

 

[Big Monk]

This was a tricky one for the calculators. Nobody got it right. Bill was 90% base malt and 10% flaked wheat.

9.158 kg Pilsner Malt (Avangard) (1.7 SRM) 70%
2.616 kg Pale Ale (Dingemans) (3.3 SRM) 20%
1.308 kg Wheat, Flaked (1.6 SRM) 10%

Strike volume 38L
Sparge volume 50L

Base water (these are annual averages for 2018 for my location from water authority website)
Ca2+ 6.9
Mg2+ 1.14
Na+ 4.8
K+ 0.43
SO2- 0
Cl- 6.3
Alkalinity as CaCO3 25.08 (converted from Total Alkalinity)
NO3- 0.72

Salts added to mash water:
Gypsum 5 grams
Calcium Chloride 7 grams
Epsom 4 grams
NaCl 4 grams

Lactic Acid
Mash 9.5 mL
Sparge 1.5 mL

Tried multiple water calculators aiming for 5.4 mash, calculating for pH lactic acid requirements
Bru'n Water 2.5 mL
Brewers Friend 9 mL
Beersmith 10 mL
Water Engine 15 mL
I went with 9.5 mL based on the range

pH measurements - Apera meter, calibrated before brewing
10 min 5.08 at 17.1C
20 min 5.19 at 17.4C
30 min 5.22 at 18.4C and 15.4 Brix 1.061
75 min 5.26 at 17.2C and 19.0 Brix 1.076

For a rebrew I guess I'd go with 6mL lactic on this recipe

Final runnings pH 5.5

Kettle ph 5.35 at 18.1C and 10.1 Brix
Added 3mL lactic and brought kettle pH to 5.18

What is the pH of the source water?

 

[eric19312]

What is the pH of the source water?

7.1 on water report 6.9 tested in the kettle before I added the salts

 

[ajdelange]

You don't need a calculator, Gen I or Gen II, to know that 5.2 is not likely the pH of this mash. You've got 12.25 kg of malts in there none of which is at all acidic. The malts specified typically have a DI mash pH of 5.65 or so and buffering of around -40 mEq/kg•pH. Thus getting to pH 5.2 would require about 40*12.25*(5.65 - 5.4) = 220 mEq protons. There is also 38 L of water with alkalinity reported as "Alkalinity as CaCO3 25.08 (converted from Total Alkalinity)". Given that total alkalinity is alkalinity (there is no conversion involved) there is some question as to what the actual alkalinity is but taking him at his word that the alkalinity is 0.5 mEq/L there's an additional deficit of 0.9*.5*38 = 17 mEq. Protons needed to get to 5.2 is thus going to be around 240. What do we have to provide those protons in this mash? Nothing by 9.5 mL of lactic acid which, at pH 5.2 is 11.3 N and thus provides 108 mEq = less that half of what is needed. Unless 1.3 kg of flaked wheat is really acidic and can supply about 130 mEq of acid 5.2 is a very unlikely pH for this mash.

So, no wonder the other calculators "got it wrong". They all estimate the properties of malts one way or another and with varying degrees of accuracy but their estimates are all derived from observations of normal malts - the malts home brewers actually use in brewing. Based on typical grains the pH of this mash (with 9.5 mL lactic acid) is likely to be between 5.4 and 5.5 depending on the actual properties of the grains. Thus you might need a bit more than 9.5 mL lactic acid, again depending on actual grain properties.

In cases like this I always look first at the pH measurements. When brewing if ever I see a pH reading off by as much as 0.2 or more from what common sense tells me to expect the first thing I do is rinse the probe and put it back into 4 buffer. If it passes that check then it is back to trying to figure out what is wrong with the mash. Did I add 19 mL of acid instead of 9 etc.

Was the meter recently calibrated following the manufacturer's instruction or those in the Sticky? Has it had a fairly recent stability check? Is the junction clogged or is the bulb dirty?...

PS: source water pH has, except in cases of unusually high or low value, very little to do with mash pH. A good calculator will, of course, take it into account but it isn't going to explain a discrepancy of this magnitude.

 

[Pappers_]

This is an excellent thread, thanks to everyone participating

 

[Silver_Is_Money]

This was a tricky one for the calculators. Nobody got it right. Bill was 90% base malt and 10% flaked wheat.

9.158 kg Pilsner Malt (Avangard) (1.7 SRM) 70%
2.616 kg Pale Ale (Dingemans) (3.3 SRM) 20%
1.308 kg Wheat, Flaked (1.6 SRM) 10%

Strike volume 38L
Sparge volume 50L

Base water (these are annual averages for 2018 for my location from water authority website)
Ca2+ 6.9
Mg2+ 1.14
Na+ 4.8
K+ 0.43
SO2- 0
Cl- 6.3
Alkalinity as CaCO3 25.08 (converted from Total Alkalinity)
NO3- 0.72

Salts added to mash water:
Gypsum 5 grams
Calcium Chloride 7 grams
Epsom 4 grams
NaCl 4 grams

Lactic Acid
Mash 9.5 mL
Sparge 1.5 mL

Tried multiple water calculators aiming for 5.4 mash, calculating for pH lactic acid requirements
Bru'n Water 2.5 mL
Brewers Friend 9 mL
Beersmith 10 mL
Water Engine 15 mL
I went with 9.5 mL based on the range

pH measurements - Apera meter, calibrated before brewing
10 min 5.08 at 17.1C
20 min 5.19 at 17.4C
30 min 5.22 at 18.4C and 15.4 Brix 1.061
75 min 5.26 at 17.2C and 19.0 Brix 1.076

For a rebrew I guess I'd go with 6mL lactic on this recipe

Final runnings pH 5.5

Kettle ph 5.35 at 18.1C and 10.1 Brix
Added 3mL lactic and brought kettle pH to 5.18

I quickly passed this recipes source water (volume and mineralization), the added mineralization, and the grist through Mash Made Easy 5.30 late last night, and (depending upon a few minor variable assumption variations) I was generally seeing an overall need for approximately 11.5 to 12.5 mL of 88% Lactic Acid when a target mash pH of 5.4 was selected.

 

[SanPancho]

I use liquid acid as well and would see a ph rise.

 

[eric19312]

You don't need a calculator, Gen I or Gen II, to know that 5.2 is not likely the pH of this mash. You've got 12.25 kg of malts in there none of which is at all acidic. The malts specified typically have a DI mash pH of 5.65 or so and buffering of around -40 mEq/kg•pH. Thus getting to pH 5.2 would require about 40*12.25*(5.65 - 5.4) = 220 mEq protons. There is also 38 L of water with alkalinity reported as "Alkalinity as CaCO3 25.08 (converted from Total Alkalinity)". Given that total alkalinity is alkalinity (there is no conversion involved) there is some question as to what the actual alkalinity is but taking him at his word that the alkalinity is 0.5 mEq/L there's an additional deficit of 0.9*.5*38 = 17 mEq.

I suspect I am describing the alkalinity entry wrong but pretty sure I am using the calculator correctly. My water report says Alkalinity, Total mg/mL 25.1. In Bru'n Water I enter this value into cell A28 and calculate Bicarbonate concentration in PPM which gets entered into cell C6. In Derek'w Water Engine I entered 25.1 into Alkalinity as CaCO3. In both cases I got a good match in the anion to cation ratio and the numbers were about the same 0.66 cations vs 0.69 anions.

Protons needed to get to 5.2 is thus going to be around 240. What do we have to provide those protons in this mash? Nothing by 9.5 mL of lactic acid which, at pH 5.2 is 11.3 N and thus provides 108 mEq = less that half of what is needed. Unless 1.3 kg of flaked wheat is really acidic and can supply about 130 mEq of acid 5.2 is a very unlikely pH for this mash.

Doesn't this analysis leave out the brewing salts? I'm using tap water with added gypsum and calcium chloride. I know these have impact on pH. My mash water was over 100 ppm Calcium.

So, no wonder the other calculators "got it wrong". They all estimate the properties of malts one way or another and with varying degrees of accuracy but their estimates are all derived from observations of normal malts - the malts home brewers actually use in brewing. Based on typical grains the pH of this mash (with 9.5 mL lactic acid) is likely to be between 5.4 and 5.5 depending on the actual properties of the grains. Thus you might need a bit more than 9.5 mL lactic acid, again depending on actual grain properties.

With 9.5 mg lactic acid the calculators estimated my mash pH would be:
Bru'n Water 5.04
Brewers Friend 5.39
Beersmith 5.42
Water Engine 5.538
And my measured pH at 30 minutes was 5.22

In cases like this I always look first at the pH measurements. When brewing if ever I see a pH reading off by as much as 0.2 or more from what common sense tells me to expect the first thing I do is rinse the probe and put it back into 4 buffer. If it passes that check then it is back to trying to figure out what is wrong with the mash. Did I add 19 mL of acid instead of 9 etc.

No way on over dosing acid. I did just run out to the garage and recheck my probe calibration. Full disclosure I did a bad thing and left my probe in a wort sample overnight. I think it must of been the kettle sample. Anyway after a rinse and checking against the pH 4 buffer I got 4.05 at 10C. Cleaned and back into proper storage solution now. Anyway it was probably within 0.02 yesterday during the brew.

Was the meter recently calibrated following the manufacturer's instruction or those in the Sticky? Has it had a fairly recent stability check? Is the junction clogged or is the bulb dirty?...

Yes new meter calibrated when first bought and ran successful 24 hour stability test as per the sticky about 3 weeks ago. Stored in storage solution since then and did not dry out. Meter calibrated in morning before brew started. Not dirty this was first use of the meter in wort.


I do have an engineering background and am pretty careful measuring everything I can think of on brew day. I get the rationale for questioning the measurement, instrument, any other variables when result doesn't match prediction. But first consider the widely different predictive results of the four water calculators used. That isn't on me or my technique...that's is just the math.

 

[dmr]

This was a tricky one for the calculators. Nobody got it right. Bill was 90% base malt and 10% flaked wheat.

9.158 kg Pilsner Malt (Avangard) (1.7 SRM) 70%
2.616 kg Pale Ale (Dingemans) (3.3 SRM) 20%
1.308 kg Wheat, Flaked (1.6 SRM) 10%

Strike volume 38L
Sparge volume 50L

Base water (these are annual averages for 2018 for my location from water authority website)
Ca2+ 6.9
Mg2+ 1.14
Na+ 4.8
K+ 0.43
SO2- 0
Cl- 6.3
Alkalinity as CaCO3 25.08 (converted from Total Alkalinity)
NO3- 0.72

Salts added to mash water:
Gypsum 5 grams
Calcium Chloride 7 grams
Epsom 4 grams
NaCl 4 grams

Lactic Acid
Mash 9.5 mL
Sparge 1.5 mL

Tried multiple water calculators aiming for 5.4 mash, calculating for pH lactic acid requirements
Bru'n Water 2.5 mL
Brewers Friend 9 mL
Beersmith 10 mL
Water Engine 15 mL
I went with 9.5 mL based on the range

pH measurements - Apera meter, calibrated before brewing
10 min 5.08 at 17.1C
20 min 5.19 at 17.4C
30 min 5.22 at 18.4C and 15.4 Brix 1.061
75 min 5.26 at 17.2C and 19.0 Brix 1.076

For a rebrew I guess I'd go with 6mL lactic on this recipe

Final runnings pH 5.5

Kettle ph 5.35 at 18.1C and 10.1 Brix
Added 3mL lactic and brought kettle pH to 5.18

I've run your above data through my (still under development and not ready for release) version 4.0 of MpH. I obtain a predicted mash pH of 5.31, which is not too far off from your later pH measurements. Or to turn it around, I predict it would have taken 7.0 mL of Lactic acid to hit a mash pH of 5.4. Given your measured pH values, I estimate about 5 ml lactic acid would have resulted in a mash pH close to 5.4.

With 9.5 mg lactic acid the calculators estimated my mash pH would be:
Bru'n Water 5.04
Brewers Friend 5.39
Beersmith 5.42
Water Engine 5.538
And my measured pH at 30 minutes was 5.22

BTW, Beersmith's calculations are based on MpH 3.0, and using that I estimate a mash pH of 5.39 (vs Beersmith's 5.42 in your last post). I can tell you I believe (at this point) that MpH 3.0 overestimates the buffering capacity of the typical grist (and so would suggest more acid than is actually required). I believe this is also the case for Brewer's Friend (based on my observations that Brewer's Friend and MpH 3.0 typically give very similar results).

I'll also say this. Based on working with mash pH data that has been posted so far in this thread, I suspect the best that any generally useful mash predictor will be able to do is a standard deviation of about 0.15 between actual and predicted pH values. There are typically too many unknowns to do much better. One of the most important of these is the distilled-water pH of the base grain. Owing to differing amounts lactic acid bacteria that develop on the growing grain, the distilled-water mash pH can vary quite appreciably [See J.B. South, J. Inst. Brewing 102, 155 (1996)]. The effect of this is that different measurements of one particular malt (Weyermann pils, e.g.) are likely to show variations (i) among bags of malt, (ii) from growing location to growing location, (iii) from season to season, etc.

The upside to such variation is that nailing down mash pH to less that 0.1 or even 0.2 units of pH is not all that important, anyway. You were shooting for 5.4, and you hit 5.2. Nothing at all wrong with that.

Happy Brewing!

 

[ajdelange]

Doesn't this analysis leave out the brewing salts? I'm using tap water with added gypsum and calcium chloride. I know these have impact on pH. My mash water was over 100 ppm Calcium.

The back of the envelope calculations did but the statement that the range of this mash would be expected to be between 5.4 and 5.5 did not. Actually calcium and magnesium have quite small effects. Not enough to bring pH down by 0.2.

With 9.5 mg lactic acid the calculators estimated my mash pH would be:
Bru'n Water 5.04
Brewers Friend 5.39
Beersmith 5.42
Water Engine 5.538
And my measured pH at 30 minutes was 5.22

But first consider the widely different predictive results of the four water calculators used.

Believe me, I do. I have stated this here so many times that I am getting a bit tired of doing so over and over again but a pH estimator is an algorithm into which you put data about your malt, your water and your additions. There are two big sources of error: the data you put in and the processing algorithm. There are not entirely independent. If you enter pale ale malt then about the only way you could have screwed up was if it was really pilsner malt or caramel malt. Some programs are only able to distinguish between malts at that levell of sophistication. As there is so much variability in pale ale malts clearly just telling a program that you are using pale ale malty isn't going to give you very good answers most of the time. The errors induced by making some assumptions about the "acid properties" of the malts are then compounded when they are inserted into a naive algorithm that tries to predict pH without much regard for the chemical processes that set pH. The popular programs all suffer from both these error sources.

I think you have to take Bru'n water out of the pack as it is so far out of line with what the others predict that there is clearly something wrong with it. A program that robustly models the acid base chemistry of malts, lactic acid and water alkalinity says the the pH of your mash will be 5.47. But that program doesn't know what your pale ale malt's properties are. It knows, in detail, the acid base properties (titration curves) that it is clear that there is at least 0.1 and probably more possible deviation from that given the grain types that you have specified. Thus 5.39, 5.42, and 5.538 are all reasonable pH estimates for your mash. 5.04 isn't and neither is 5.22.

That isn't on me or my technique...that's is just the math.

You don't know that. In fact it probably is on you as the back of the envelope calculation (and a more detailed one that looks at the proton deficit of each component of your mash) suggest. Over a hundred mEq of protons have shown up in your mash which have no apparent source. As an engineer you should know that when things don't compute there is probably something wrong and you should want to find out what it is. In any case there is a discrepancy here that I would think you would want an explanation for. There are lots of people here who will try to help you find it. Yes, the math has its shortcomings but when programs with the correct math are used you get answers that are too far away from 5.22 to be shrugged off as a problem with the math.

 

[Silver_Is_Money]

I can also get the @eric19312 recipe to mash at a pH of 5.40 in Mash Made Easy 5.30 with only 7 mL of 88% Lactic Acid, but only if I cut back on the Pilsner base malts DI_pH to 5.63, and the Pale Ale base malt to 5.62, as can be seen below. These changes were easily made via using the base malt DI_pH modifier 'drop down' cell in the lower right hand corner of MME.

@dmr, what did you assume the Pilsner and Pale Ale malts respective DI_pH's to be for your test run of MpH 4.0? And ditto for the Flaked wheat...

 

[Big Monk]

I can also get the @eric19312 recipe to mash at a pH of 5.40 in Mash Made Easy 5.30 with only 7 mL of 88% Lactic Acid, but only if I cut back on the Pilsner base malts DI_pH to 5.63, and the Pale Ale base malt to 5.62, as can be seen below. These changes were easily made via using the base malt DI_pH modifier 'drop down' cell in the lower right hand corner of MME.

@dmr, what did you assume the Pilsner and Pale Ale malts respective DI_pH's to be for your test run of MpH 4.0? And ditto for the Flaked wheat...

View attachment 610612

That’s pretty low for euro base malts though.

I would imagine either of those to be below 5.75 and much more likely > 5.80.

 

[eric19312]

I think you have to take Bru'n water out of the pack as it is so far out of line with what the others predict that there is clearly something wrong with it..

Oddly Bru’n Water was closest to measured pH. But toss that one and keep the rest?

 

[Silver_Is_Money]

Oddly Bru’n Water was closest to measured pH. But toss that one and keep the rest?

Flaked Wheat, being unmalted, generally has a rather noticeably high pH. How does BW account for the inherently high pH of Flaked Wheat? Does it still default it to just another base malt (as if it was malted barley, and as such more acidic)?

 

[dmr]

I can also get the @eric19312 recipe to mash at a pH of 5.40 in Mash Made Easy 5.30 with only 7 mL of 88% Lactic Acid, but only if I cut back on the Pilsner base malts DI_pH to 5.63, and the Pale Ale base malt to 5.62, as can be seen below. These changes were easily made via using the base malt DI_pH modifier 'drop down' cell in the lower right hand corner of MME.

@dmr, what did you assume the Pilsner and Pale Ale malts respective DI_pH's to be for your test run of MpH 4.0? And ditto for the Flaked wheat...

Unless I have a very good reason to do otherwise, I assume the distilled-water pH of Pils/Lager/2-row malts to be 5.72. That is what I assumed in my calculations for eric19312's beer. Why? Because I feel that is a good average distilled-water mash pH for malts in this category. Sure, some are higher and some are lower, but as I discussed above, unless one has an actual measurement of grain from your own bag of malt, I don't think one can really do any better.

Similarly, I assume malts in the Pale Ale/Vienna/Mild category have a distilled-water mash pH of 5.69.

I assumed the flaked wheat pH to be 6.57, which is what my collaborator on our recent paper measured. Distilled-water pH is not the whole story, though, as the buffering capacity of the flaked wheat we measured is about 60% of that of malts in the pils/lager/2-row category. Generally, differences in buffering capacity must be accounted for when modeling mash pH.

 

[eric19312]

Flaked Wheat, being unmalted, generally has a rather noticeably high pH. How does BW account for the inherently high pH of Flaked Wheat? Does it still default it to just another base malt (as if it was malted barley, and as such more acidic)?

I selected "wheat/oat" as the category. Didn't have a flaked wheat option.

 

[micraftbeer]

In another thread, someone suggest I post my Pilsner that came out with an ultra low mash pH using the acid predictions I got from BeerSmith 2. I've had hit or miss luck with BS2 predicting mash pH. Sometimes spot on, but other times asking me to dump a bunch of acid in. This is a case where it asked for a lot of acid.

Pilsner Recipe
13.5 lbs German Pilsner
0.5 lbs Carahell
0.15 lbs Dark Munich
8.3 gallons of tap water (after 3-filter activated carbon filtration).
LaMotte water test says: 30 ppm Chloride, 0 ppm Sulfate, Total Alkalinity 80 ppm (as CaCO3), Total Hardness 70 ppm (as CaCO3), Ca ions 24 ppm, Mg ions 2.42 ppm, Residual Alkalinity 61.4 ppm (as CaCO3), Sodium 24.38 ppm
4.1 g Gypsum
7.1 g Epsom
1.7 g CaCl
4.9 oz (145 ml) of 10% Phosphoric Acid
Mash @ 151F
@ 18 min into mash: pH=4.41 @ 24.6C
@ 30 min into mash: pH=4.59 @ 19.2C
@ 90 min into mash: pH = 4.86 @ 22.2C