Dry Irish Stout Full volume mashing and Low Alkalinity

[Gavin C]

I am brewing a dry Irish stout this coming weekend.

Initially I thought of using my tap water as is with its moderate level of alkalinity.

My Water


Fortunately I found this marvelous presentation by @mabrungard from 2013

http://www.homebrewersassociation.org/attachments/presentations/pdf/2013/1715-24%20Historic%20Water%20-%20Martin%20Brungard.pdf

I plan on using a low alkalinity profile (Wicklow Mountains)

With a usual mash grist/water ratio separate mashing of base and roast malts will prevent the pH from getting too low with this soft water profile.

My question is this.

If I mash full volume as I usually do (no-sparge), would this negate the need to mash the base malts separately to the roast malts while still being able to use a soft water profile and keep the mash pH in a favorable range for a dry Irish stout.

The numbers seem to support this but I'm wondering am I missing out on some flavor/mouthfeel by not separating the mash in to its base (Maris Oter and Flaked Barley) and roast constituents.

Water Calculations


Predicted Mash pH


Mash Volume


Mash Profile

Any input is greatly appreciated. My current plan is a single infusion mash. (No separation of the grist)

 

[Gnomebrewer]

A little off topic here....well, sort of.....

I've been brewing a few pale-lagers lately, including your (Gavin's) Helles, which I know you've had great success with using full-volume BIAB. My pH measurements got me thinking about full volume mashing - you use quite a lot of acid in your mash to keep pH down on those pale beers, and presumably get a good kettle pH. I have found (with a 2.6L/Kg water:grist mash ratio) that I still have to add a lot of acid to the boil to get a reasonable boil pH on pale beers, even when my mash pH was spot-on, using very soft water. In fact, my TOTAL acid addition ends up being about the same as your mash acid addition. With mid-coloured beers (APA, bitters etc.) the boil pH falls into line if my mash pH is good.

So, how does this relate to your situation with the stout? I wonder if you might have the opposite problem with you boil pH - will you need to add alkalinity to the kettle to stop the boil pH dropping too low? I might be overthinking things here. On the other hand, if your mash pH is good, the pH should be the same (using full volume mash) going into the kettle.

 

[Gavin C]

A little off topic here....well, sort of.....

I've been brewing a few pale-lagers lately, including your (Gavin's) Helles, which I know you've had great success with using full-volume BIAB. My pH measurements got me thinking about full volume mashing - you use quite a lot of acid in your mash to keep pH down on those pale beers, and presumably get a good kettle pH. I have found (with a 2.6L/Kg water:grist mash ratio) that I still have to add a lot of acid to the boil to get a reasonable boil pH on pale beers, even when my mash pH was spot-on, using very soft water. In fact, my TOTAL acid addition ends up being about the same as your mash acid addition. With mid-coloured beers (APA, bitters etc.) the boil pH falls into line if my mash pH is good.

So, how does this relate to your situation with the stout? I wonder if you might have the opposite problem with you boil pH - will you need to add alkalinity to the kettle to stop the boil pH dropping too low? I might be overthinking things here. On the other hand, if your mash pH is good, the pH should be the same (using full volume mash) going into the kettle.

No idea I'm afraid. Kettle pH/beer pH is something I have never measured. I only ever measure mash pH.

 

[mabrungard]

One of my clubmates, a former Indiana Homebrewer of the Year, recently brewed a dry stout using that method and I had the opportunity to taste it. It was remarkably similar to the character and flavor of Guinness. I can attest that this method does work very well for this style. I think you will be pleased with the result.

 

[Gavin C]

One of my clubmates, a former Indiana Homebrewer of the Year, recently brewed a dry stout using that method and I had the opportunity to taste it. It was remarkably similar to the character and flavor of Guinness. I can attest that this method does work very well for this style. I think you will be pleased with the result.

Thanks Martin. Just so I'm clear on your meaning, you're suggesting I split the mash in the manner you outlined in your 2013 presentation.

 

[ajdelange]

I am brewing a dry Irish stout this coming weekend.

Initially I thought of using my tap water as is with its moderate level of alkalinity.

That would work just fine. That assumes, of course, that you are using a reasonable proportion of roast barley such as in Ashton Lewis's recipe in Michael Lewis's monograph in the AHA series.

I plan on using a low alkalinity profile (Wicklow Mountains)

You already have a low alkalinity profile but if you want to fool around with profiles I guess that's OK. With your water and your recipe mash pH is going to come in at about 5.5 - 5.6 so you really need a little acid but I have similar water and find the beer is OK without pH adjustment so I don't bother. This is not to say that it might not be better if I went a bit lower but as it is pretty darn good as is why mess with success? Unless you brew it frequently enough that you want to experiment.

With a usual mash grist/water ratio separate mashing of base and roast malts will prevent the pH from getting too low with this soft water profile.

Again, I don't know how much roast barley you are using but if you keep it at or below 10% the pH isn't going too low even if you mash it all together. In fact if you withhold the roast barley mash pH for the rest of the grain will probably be too high.

If I mash full volume as I usually do (no-sparge), would this negate the need to mash the base malts separately to the roast malts while still being able to use a soft water profile and keep the mash pH in a favorable range for a dry Irish stout.

If by this you mean that you are going to mash with the entire volume of water then I would be concerned about mash pH going to high with the roast malts in there. Of course if you did a conventional mash you would still be wanting some acid in the kettle to keep kettle pH low.

The numbers seem to support this but I'm wondering am I missing out on some flavor/mouthfeel by not separating the mash in to its base (Maris Oter and Flaked Barley) and roast constituents.

I know Gordon Strong and others advocate separating the dark malt from the rest of the grist but I don't see any reason to do that if you are using reasonable amounts of roast barley. At 10% you get all the color, all the flavor and no harshness whatsoever (unless you get it from the hops).

I've done Irish Stout this way for years and it is so like Guiness that I got dinged in one competition because my beer "Tastes like Guiness". One of the reasons I no longer enter competitions.

I just want to be clear that I am not discouraging experimentation if that's your goal.

 

[Gavin C]

Lots of great advice...................

I just want to be clear that I am not discouraging experimentation if that's your goal.

@AJdelange

Thank you for the thoughtful and extensive reply. My apologies for omitting the recipe. Figures are aproximate but pretty close to where I'm at.

65% Maris Oter (~3L)
25% Flaked Barley (~2L)
10% Roast Barley (~500L)

You are absolutely right I am probably tinkering with things a bit too much but that is something I like to do especially WRT to water profiles and mash profiles. I try to explore a little bit each time I brew as I am relatively inexperienced and have a great deal to learn.

I was surprised to learn of the soft water profile for Guiness having so often read the line of Dublin/Ireland being known for dark beers owing to the hard water that proliferates.

There was always a bit of a disconnect in my mind, as I grew up just a few miles west of the Guinness James' Gate Brewery and we never had issues with water hardness in our home.

Learning that Guinness is made with a soft water profile coming from the Granite rich Wicklow mountains shouldn't be too much of a surprise to me I suppose. Reading Martin's presentation sure did make the pieces click together.

Acid Malt
I use acid malt in all my beers with stouts being the only style I have not needed any to date. Full volume mashes demand some acid and I favor the use of acid malt. I've enjoyed tasty results even with light lagers and acid malt in amounts much higher than the typical 1-2% so often used.

A pH of 5.5 is about what I was shooting for on the stout. With my tapwater a little acid malt would be needed. With the RO dilution it seems to be where I want it without.

I was just wondering if the full-volume mash acomplishes largely the same thing as the separate mash/steep idea where the wort from both are subsequently blended.

I doubt I am skilled enough as a taster to discern any difference. Fun to explore the idea nonetheless.

Thanks again for your help.

 

[mabrungard]

Thanks Martin. Just so I'm clear on your meaning, you're suggesting I split the mash in the manner you outlined in your 2013 presentation.

I don't recall what that presentation recommended, but what I'm recommending is mashing all the pale grains at a proper pH of around 5.4 and then adding the roast malt at the end of the mashing period to extract the color and flavor. Of course that late addition drives down the wort pH, but that's OK in a dry stout.

 

[Gavin C]

I don't recall what that presentation recommended, but what I'm recommending is mashing all the pale grains at a proper pH of around 5.4 and then adding the roast malt at the end of the mashing period to extract the color and flavor. Of course that late addition drives down the wort pH, but that's OK in a dry stout.

Gotcha. I was reading some of the AHA discussion boards in which you were involved too so perhaps that was where the method was discussed.

Thanks again for your time. Very much appreciated.

 

[ajdelange]

75% Maris Oter (~3L)
25% Flaked Barley (~2L)
10% Roast Barley (~500L)

I assume you mean 15% flaked barley. This is, IIRC, pretty close to the Lewis recipe.

I was just wondering if the full-volume mash acomplishes largely the same thing as the separate mash/steep idea where the wort from both are subsequently blended.

Were you to mash this grist normally (1.5 qts/lb) you would get a mash pH of about 5.6 if you do not separate the dark malts and about 5.7 if you do. The former is marginal IMO and the latter too high meaning that the MO and flaked barley would not develop their full flavor potentials. Nor, I expect would the roast barley when it was added later because it hasn't been mashed as long as it normally would be. Why would you want to hold it out? If it is fear of Gordon's "coffee at the office that's sat in the carafe overnight night" premise I can assure you that this will not be the case.

Now if you mash with the full volume of water (and I'm going to assume that that is 3 qts/lb of grain) the effect on pH is to double the proton deficit required of the water which (I assumed alkalinity of 1 mVal) is going to bring mash pH, with the dark malt included, to an estimated 5.8 - too high. Were the alkalinity half that (0.5 mval) then the estimated mash pH would be 5.7 - still too high but better. So I think it's pretty clear that you do not want to mash with the full volume of water nor mash with the normal 1.5 qts/lb and withhold the roast barley unless you add acid to compensate for the acid of the roast barley in the mash and/or for the extra alkalinity in the extra mash water.

I doubt I am skilled enough as a taster to discern any difference.

I'll bet you are. Lot's of people have reported that the difference between pH's in the 5.5 region as opposed to the 5.7 are dramatic. That certainly was the case for me.

Fun to explore the idea nonetheless.

Absolutely

 

[Gavin C]

I assume you mean 15% flaked barley. This is, IIRC, pretty close to the Lewis recipe.



Were you to mash this grist normally (1.5 qts/lb) you would get a mash pH of about 5.6 if you do not separate the dark malts and about 5.7 if you do. The former is marginal IMO and the latter too high meaning that the MO and flaked barley would not develop their full flavor potentials. Nor, I expect would the roast barley when it was added later because it hasn't been mashed as long as it normally would be. Why would you want to hold it out? If it is fear of Gordon's "coffee at the office that's sat in the carafe overnight night" premise I can assure you that this will not be the case.

Now if you mash with the full volume of water (and I'm going to assume that that is 3 qts/lb of grain) the effect on pH is to double the proton deficit required of the water which (I assumed alkalinity of 1 mVal) is going to bring mash pH, with the dark malt included, to an estimated 5.8 - too high. Were the alkalinity half that (0.5 mval) then the estimated mash pH would be 5.7 - still too high but better. So I think it's pretty clear that you do not want to mash with the full volume of water nor mash with the normal 1.5 qts/lb and withhold the roast barley unless you add acid to compensate for the acid of the roast barley in the mash and/or for the extra alkalinity in the extra mash water.




I'll bet you are. Lot's of people have reported that the difference between pH's in the 5.5 region as opposed to the 5.7 are dramatic. That certainly was the case for me.


Absolutely

Sorry for my error. 65% MO 25% flaked barley 10% Roast Barley. (Not set in stone, this was what my research led me to for Guinness).

About not being able to tell the difference. I meant assuming That I adequately control pH at or around 5.5 as planned for either mash type I'm a doubtful I could tell the difference. I do agree that 5.7 to 5.5 would likely allow even me to taste the difference.

Looks like I need to redo the numbers with some acid malt subbed for some flaked Barley. (Or change the percentages to 75,15,10 if I have that wrong)

Bru'n water has for me been a very accurate predictive tool, (Hach Pro+ used to measure actual mash pH). I am somewhat disinclined to ignore the data its producing which are pH numbers ~5.5 for the full volume mash. I say that respectfully and with some trepidation as I have no doubt your own mash calculations (pH 5.7) are second to none.

Thanks again AJ. Looks like I have some more planning and deciding to do. I may just have to do it both ways on different brewdays and see what differences it makes.

 

[ajdelange]

Bru'n water has for me been a very accurate predictive tool, (Hach Pro+ used to measure actual mash pH). I am somewhat disinclined to ignore the data its producing which are pH numbers ~5.5 for the full volume mash. I say that respectfully and with some trepidation as I have no doubt your own mash calculations (pH 5.7) are second to none.

My algorithms are more robust than Bru'n Water's and my data is based on actual measurements of real malts (as opposed to guesses about the properties based on malt type or color) so my answers have to be more accurate, no? No! I know better than to claim that they are any more accurate than guesses as I understand the underlying mechanisms responsible for producing a given mash pH pretty well. Bru'n water cannot be a very accurate predictive tool and neither can AJ's robust algorithm because of the nature of the problem, in particular variability of and therefore uncertainty about the grains. If I make a laboratory mash using the same grain lots on which I have made measurements, sure, I get pH predictions that are ± 0.01 or ± 0.02 pH. But if I try to do that with the same malt from the same maltster using a lot of the same malt produced a year later it doesn't work so well (that's why I want the maltsters to put the data on the sacks). So when someone reports that a program is a very accurate mash pH prediction tool something is wrong. I don't know exactly what that is but I strongly suspect that it has something to do with the all powerful confirmation bias. You want it to be accurate so you make it so, quite unintentionally, of course. This is something scientists are terrified of (scrupulous ones anyway) and go to great pains to avoid being the victim of. It is for such things that the double blind experimental procedures were developed. I don't know if you have any technical training but if you do you will have been taught that when things look too good to be true they usually aren't and you'd better start trying to find out why. With respect to the double blind thing I've had occasion this week to mention Der Kluge Hans so I'll mention him again. Look him up. It's entertaining and I think he was a rather handsome fellow.

 

[Gavin C]

My algorithms are more robust than Bru'n Water's and my data is based on actual measurements of real malts (as opposed to guesses about the properties based on malt type or color) so my answers have to be more accurate, no? No! I know better than to claim that they are any more accurate than guesses as I understand the underlying mechanisms responsible for producing a given mash pH pretty well. Bru'n water cannot be a very accurate predictive tool and neither can AJ's robust algorithm because of the nature of the problem, in particular variability of and therefore uncertainty about the grains. If I make a laboratory mash using the same grain lots on which I have made measurements, sure, I get pH predictions that are ± 0.01 or ± 0.02 pH. But if I try to do that with the same malt from the same maltster using a lot of the same malt produced a year later it doesn't work so well (that's why I want the maltsters to put the data on the sacks). So when someone reports that a program is a very accurate mash pH prediction tool something is wrong. I don't know exactly what that is but I strongly suspect that it has something to do with the all powerful confirmation bias. You want it to be accurate so you make it so, quite unintentionally, of course. This is something scientists are terrified of (scrupulous ones anyway) and go to great pains to avoid being the victim of. It is for such things that the double blind experimental procedures were developed. I don't know if you have any technical training but if you do you will have been taught that when things look too good to be true they usually aren't and you'd better start trying to find out why. With respect to the double blind thing I've had occasion this week to mention Der Kluge Hans so I'll mention him again. Look him up. It's entertaining and I think he was a rather handsome fellow.

I'll google that fellow later on and explore confirmation bias some more. Thanks.

Acurate is a relative term I guess. Typically Bru'n Water comes in a hair above actual pH as I measure it but this seems to relatively constant thing.

I'm not in a postion to test my malt nor am I knowledgeable enough to do anything with that data were I to have it. What I do have is a reasonably sound meter (well it was until the probe stopped measuring temperature so I need a new one) and a piece of software I use to get me close to where I need to be.

For me this is going to be as accurate as I get as I believe the variable subject to greatest inconsistency may well be me and my ingredients.

I also believe (and I may be miles off base here) that the various predictive tools out there are more geared toward a typical water/grist ratio. With full volume mashes and a ratio with more than twice as much water, perhaps the algorithms become less precise as predictive tools. That may very well be complete and utter hogwash. It is pure supposition on my part. probably should keep that kind of nonsense to myself.

As you often mention, a test mash is truly the best way to get predictive information. With my batches only being 5.5 gallons it hardly seems a worthwhile endeavor. Somethiing I will do for sure but more for the experimentation fun than anything really.

Anyway sorry for my rambling.

 

[ajdelange]

Acurate is a relative term I guess. Typically Bru'n Water comes in a hair above actual pH as I measure it but this seems to relatively constant thing.

Curious as to what a 'hair' is. 0.01ph? 0.05 pH? 0.1 pH?

Also I'd like to remind people of the time aspect. Last brew I did I was a hair (0.04) under my estimate 13 minutes after dough in, 0.16 over my estimate at 30 minutes and obviously exactly on at some time in between. So do I have an accurate predictor?

I'm not in a postion to test my malt

Sure you are. I corresponding with the QC guy at a brewery who is doing the measurements with the same meter you have. But there isn't much point in you doing the measurements on all the malts and then sticking the numbers into a calculator as that's more work than a test mash which is actually the necessary measurement with all the malts mixed together in the proportions you intend to use. No, I want the maltsters to give you the data you need to use their products. For each lot number.

...nor am I knowledgeable enough to do anything with that data were I to have it.

Sure you are. Were I to get my way (and I don't think I am) the sack of Crisp Maris Otter I analyzed would have had a table stenciled on it (or the certificate of analysis would have had a table on it) that looked like

pH PD/lb
5.6 1.9
5.5 4.1
5.4 6.4
5.3 8.7

and the roast barley one like

pH PD/lb
5.6 -26.3
5.5 -22.4
5.4 -18.7
5.3 -15.2

From the first table you can trivially see that the proton deficit of Crisp Maris Otter (or at least the bag I analyzed) was 3.0 mEq/lb at pH 5.5. Multiply 3 times the number of pounds of MO you intend to use and that the amount of acid you need to hit pH 5.5. If your water's alkalinity is 1 mEq/L (50 ppm as CaCO3) you know you will need 0.9 mEq/L of water used in acid to take care of that alkalinity. Looking at the roast barley table you see that its proton deficit at pH 5.5 is -24.35 mEq/Lb i.e. it has a proton surfeit which can cancel the deficit. If your water and MO deficits total Y mEq you know that you will need Y/24.35 lbs of roast barley to cancel them. It's that simple.

For me this is going to be as accurate as I get as I believe the variable subject to greatest inconsistency may well be me and my ingredients.

The programs out there now ignore non linearity in the malt buffering, don't pay any attention to the individual malt's temperature vs pH characteristics, use buffering data obtained by Kai years ago using eye droppers and hydrorochloric acid from the hardware store, and don't recognize that the pH setting reaction takes appreciable time. All those I can fix (to some extent). I cannot fix the fact that today's sack of Crisp MO isn't the same as last year's.

I also believe (and I may be miles off base here) that the various predictive tools out there are more geared toward a typical water/grist ratio. With full volume mashes and a ratio with more than twice as much water, perhaps the algorithms become less precise as predictive tools.

A properly executed calculator would not have that problem.

That may very well be complete and utter hogwash. It is pure supposition on my part. probably should keep that kind of nonsense to myself.

Not at all. It's a good point. I believe some of them use empirical data to a large extent.

Anyway sorry for my rambling.

I very much value your thoughts. You are, I believe, saying that Bru'n water can do things that it is pretty plain that it, nor any other program, can and I'd like to know how you, and others, came to have that opinion.

 

[mabrungard]

AJ, I see that you are seeing that time-dependent mash pH variation as I've seen. It's a curious phenomena, but chemistry is complicated. I'm curious how this inter-relates with the tendency of initially high or initially low mash pH to self correct toward a pH of about 5.4? There is still plenty more to explore on this subject.

 

[mabrungard]

I also believe (and I may be miles off base here) that the various predictive tools out there are more geared toward a typical water/grist ratio. With full volume mashes and a ratio with more than twice as much water, perhaps the algorithms become less precise as predictive tools.

I've set up Bru'n Water to assess the total quantities of acidity provided by the grist, mineral additions, and acids and that is contrasted with the total quantity of alkalinity provided by the mashing water volume and its alkalinity. It is that tally of acidity and alkalinity that is empirically related to pH.

It has proven to be reasonably accurate without respect to varying water/grist ratio. Of course, that is for ratios that are more typical to regular mashing methods. The advent of BIAB and no-sparge might exceed the analyses' capability. I'll look forward to measurements and comparisons, when you have them.

 

[ajdelange]

Martin,

We're dumping quite a few things (water with dissolved bicarbonate ion, base malt, colored malt(s), pH correction doses of acid or base) into a mash tun and sticking a pH electrode in there. We know that the measured pH changes over time and we know that it takes time for the water to access the inner parts of the malt particles, burst the matrix, render the starches soluble etc. The pH meter is, initially, going to respond to whatever goes into solution fastest. It makes sense that if you have used liquid acid or sauergut or sauermalz that has been sprayed with acid that that acid is going to go into solution much more quickly that things that are going to absorb the protons eventually and that are buried in the base malts. Hence initial pH would be low and rise over the course of the mash towards equilibrium pH.

OTOH acids in black malts and caramel malts you would think to be more deeply buried in the matrix and thus not be released until later in the mash so that if you used some bicarbonate or lime to neutralize those acids the bicarb or OH ions would be highest in the solution initially and the pH would lower over time as the alkaline ions reach the interiors of the black malts or the hydrogen ions from the black malts get out to neutralize the alkaline ions.

Certainly any time I am doing a malt titration with acid I see rising pH and any time I am using NaOH I see falling pH over time.

That's my explanation for it anyway.

 

[Gavin C]

Curious as to what a 'hair' is. 0.01ph? 0.05 pH? 0.1 pH?

Also I'd like to remind people of the time aspect. Last brew I did I was a hair (0.04) under my estimate 13 minutes after dough in, 0.16 over my estimate at 30 minutes and obviously exactly on at some time in between. So do I have an accurate predictor?

Sure you are. I corresponding with the QC guy at a brewery who is doing the measurements with the same meter you have. But there isn't much point in you doing the measurements on all the malts and then sticking the numbers into a calculator as that's more work than a test mash which is actually the necessary measurement with all the malts mixed together in the proportions you intend to use. No, I want the maltsters to give you the data you need to use their products. For each lot number.


Sure you are. Were I to get my way (and I don't think I am) the sack of Crisp Maris Otter I analyzed would have had a table stenciled on it (or the certificate of analysis would have had a table on it) that looked like

pH PD/lb
5.6 1.9
5.5 4.1
5.4 6.4
5.3 8.7

and the roast barley one like

pH PD/lb
5.6 -26.3
5.5 -22.4
5.4 -18.7
5.3 -15.2

From the first table you can trivially see that the proton deficit of Crisp Maris Otter (or at least the bag I analyzed) was 3.0 mEq/lb at pH 5.5. Multiply 3 times the number of pounds of MO you intend to use and that the amount of acid you need to hit pH 5.5. If your water's alkalinity is 1 mEq/L (50 ppm as CaCO3) you know you will need 0.9 mEq/L of water used in acid to take care of that alkalinity. Looking at the roast barley table you see that its proton deficit at pH 5.5 is -24.35 mEq/Lb i.e. it has a proton surfeit which can cancel the deficit. If your water and MO deficits total Y mEq you know that you will need Y/24.35 lbs of roast barley to cancel them. It's that simple.




The programs out there now ignore non linearity in the malt buffering, don't pay any attention to the individual malt's temperature vs pH characteristics, use buffering data obtained by Kai years ago using eye droppers and hydrorochloric acid from the hardware store, and don't recognize that the pH setting reaction takes appreciable time. All those I can fix (to some extent). I cannot fix the fact that today's sack of Crisp MO isn't the same as last year's.

A properly executed calculator would not have that problem.
Not at all. It's a good point. I believe some of them use empirical data to a large extent.




I very much value your thoughts. You are, I believe, saying that Bru'n water can do things that it is pretty plain that it, nor any other program, can and I'd like to know how you, and others, came to have that opinion.

One man's hair is another man's gulf I guess.

What I am saying it does for me is simply this.

It predicts a mash pH which typically over estimates by 0.05 to 0.1 my measured mash pH. These seems to be a relatively constant "error", for want of a better term from brew to brew.

I measure pH usually 30 minutes into the mash duration and during a mixed scarification rest (148-155°F).

My planned mash pH and measured mash pH are typically within 0.1 (usually within 0.05) of each other. Whether or not this is by hook, crook or luck I don't know. I consider this level of precision (or imprecision if you prefer) to be acceptable. I'm sure others would not share this view.

Just to clarify for me. Probably just illustrating the gaps in my knowledge here.

PD/lb = proton defecit/pound of grain ?

 

[Gavin C]

I've set up Bru'n Water to assess the total quantities of acidity provided by the grist, mineral additions, and acids and that is contrasted with the total quantity of alkalinity provided by the mashing water volume and its alkalinity. It is that tally of acidity and alkalinity that is empirically related to pH.

It has proven to be reasonably accurate without respect to varying water/grist ratio. Of course, that is for ratios that are more typical to regular mashing methods. The advent of BIAB and no-sparge might exceed the analyses' capability. I'll look forward to measurements and comparisons, when you have them.

It has proven itself very useful to me in my little brewing operation. I have predicted pH values and measured pH values for quite a few brews. I doubt my data would stack up to others' in terms of accuracy.

 

[ajdelange]

Yes, exactly wrt pd/lb.

I wouldn't consider 0.1 to be a 'hair' but I certainly feel it is accurate enough to be useful.

 

[Gavin C]

...I'll look forward to measurements and comparisons, when you have them.

I brewed the Irish Stout today.

First brew with my new Milwaukee 102 pH meter.

In the end I elected to use my usual full volume mash and did not split the grist up as discussed. I planned on a mash pH of 5.4-5.5 so targeted the upper range in Bru'n water as per my usual findings of it giving a slightly high estimate for my system

Grain Bill and Soft water profile.



Single Infusion Mash at 152°F






A fun brew. Thanks again for all the enormously useful advice. If and when I brew another I will likely do a split mash method and see which I prefer. Here are some details of today's brew if anyone is still interested.

Came in a bit under my planned 1.042

 

[joshesmusica]

Hey Gavin, how'd this one turn out? And have you brewed up another version of this yet?

 

[Gavin C]

Hey Gavin, how'd this one turn out? And have you brewed up another version of this yet?

My first batch (the recipe outlined earlier in the thread) finished too high at 1.014 and scored poorly in competition. (33.5)

Feedback included a smokey flavor, one judge dinged it badly for use of smoked malt.

My second batch. I tweaked the recipe, lowering the mash temp and using a full volume mash. Finished at 1.010 (need to check my BS file to verify) so was much more in line with what I wanted. The yorkshire yeast is not the best choice for an Irish stout.

3rd batch I will use a more appropriate yeast and add the roast grains late in the mash as discussed earlier in the thread.

 

[joshesmusica]

Weird, where do you think they got the smoke flavor from?

 

[Gavin C]

Weird, where do you think they got the smoke flavor from?

I'm not sure but both judges remarked on it being present. Was not listed as an off flavor but as an undesriable element to the style of beer in question.

My guess is adding the roasted malt to the mash at the outset and the yeast not attenuating as much as hoped played a role.

I'm hoping for a better result with my second iteration.

Next time I'm adding the roast malt late in the mash and using a yeast more true to style.