Dark Beer Problems..

[RKi]

I live in a very soft water area and am able to produce excellent pale beers. Dark beers however are currently a massive thorn in my side. Essentially i have to use what i think is a ton of Sodium Bicarbonate to achieve a mash pH in the 5.5-5.6 range and i'm starting to think that its somehow muting all of the roasted flavours in my stouts. Is that even possible? I think i can taste the bicarbonate in my dark beers, and they seem to have almost no pleasant chocolate / coffee notes and come across as harsh. I find it depressing when i open good commercial beers which blast me in the face straight away with roasted notes :\

This is the stout in question including the water profile i built up. It's based loosely upon Rogue Shakespeare Stout.

Brew Method: All Grain
Style Name: American Stout
Boil Time: 60 min
Batch Size: 12 liters (fermentor volume)
Boil Size: 15.5 liters
Boil Gravity: 1.044
Efficiency: 77% (brew house)


STATS:
Original Gravity: 1.057
Final Gravity: 1.013 (It actually finishes around 1.018-1.020)
ABV (standard): 5.84%
IBU (tinseth): 41.62
SRM (morey): 43.67

FERMENTABLES:
268 g - United Kingdom - Extra Dark Crystal 160L (9%)
372 g - Flaked Oats (12.5%)
104 g - United Kingdom - Black Patent (3.5%)
134 g - United Kingdom - Brown (4.5%)
1850 g - United Kingdom - Maris Otter Pale (62.4%)
238 g - United Kingdom - Chocolate (8%)

HOPS:
6 g - Magnum, Type: Pellet, AA: 13.4, Use: Boil for 60 min, IBU: 17.91
15 g - CTZ, Type: Pellet, AA: 14.3, Use: Boil for 15 min, IBU: 23.71

MASH GUIDELINES:
1) Fly Sparge, Temp: 69 C, Time: 60 min, Amount: 11.5 L, 7L
Starting Mash Thickness: 3.83 L/kg

OTHER INGREDIENTS:
0.25 each - Protafloc, Time: 10 min, Type: Fining, Use: Boil
0.6 g - Gypsum, Time: 60 min, Type: Water Agt, Use: Mash
1.5 g - Calcium Chloride, Time: 60 min, Type: Water Agt, Use: Mash
0.36 g - Gypsum, Time: 60 min, Type: Water Agt, Use: Boil
0.91 g - Calcium Chloride, Time: 60 min, Type: Water Agt, Use: Boil
4.4 g - Baking Soda, Time: 60 min, Type: Water Agt, Use: Mash
0.125 tsp - Brewtan B - Pre Mash, Time: 60 min, Type: Other, Use: Other
0.125 tsp - Brewtan B - Sparge, Time: 60 min, Type: Other, Use: Other
0.25 tsp - Brewtan B - Boil, Time: 15 min, Type: Other, Use: Boil

YEAST:
Fermentis / Safale - American Ale Yeast US-05
Starter: No
Form: Dry
Attenuation (avg): 81%
Flocculation: Medium
Optimum Temp: 12.22 - 25 C
Fermentation Temp: 16 C

PRIMING:
Method: Dextrose
CO2 Level: 2.1 Volumes

TARGET WATER PROFILE:
Profile Name: London + CaCl2
Ca2: 68
Mg2: 2
Na: 65
Cl: 95
SO4: 45
HCO3: 278
Water Notes:
1 ml Phosphoric = -0.18 pH
1g Baking Soda = +0.18 pH

Bru'n Water pH 5.49


I'm thinking about either adding all of my minerals to the kettle next time, or reserving all of my roasted grains until the last 15 minutes of the mash. Personally i'm leaning towards the Minerals in the kettle route. If i do that i've calculated that i can use only 3.05g of Sodium Bicarbonate, reducing HCO3 to 193 instead of 278. That would give me a mash pH of 5.4, which is a bit lower than i'd like, but i feel i need to reduce the bicarbonate.


I don't know if i'm completely off the mark with this theory though tbh, my Sodium numbers seem fine and i'm not sure if 278 HCO3 is even really a problem? Other than that, i'm considering switching to S-04 as that may favour the malt more than the hops? I'm hoping that the beer improves considerably in the bottle also in the next few weeks, although the previous stouts have only got worse....

For what its worth, all my pale beers turn out great, so i don't think its brewing process related.


Anyone ideas guys?

 

[SanPancho]

Might not be related, but you may not be getting full conversion. Adding a few %s of wheat will give you alot more diastatic power. Maris is pretty low in DP to begin with and youve got nearly 40% specialties.

 

[RKi]

Might not be related, but you may not be getting full conversion. Adding a few %s of wheat will give you alot more diastatic power. Maris is pretty low in DP to begin with and youve got nearly 40% specialties.

The sack of Maris Otter is actually from a local floor maltsters who i don't usually use/trust to be honest. I get crappy efficiency with their malt compared to my usual source. They're actually closing next month after 180 years, which is quite sad. Could that somehow be effecting the beer in the ways described above though?

 

[Silver_Is_Money]

Are you actually measuring your wort pH at ~20 minutes into the mash to confirm mashing at 5.5 pH? I would suggest cutting back on the sodium bicarbonate to about 2.5 to 2.75 grams.

 

[RKi]

Are you actually measuring your wort pH at ~20 minutes into the mash to confirm mashing at 5.5 pH? I would suggest cutting back on the sodium bicarbonate to about 2.5 to 2.75 grams.

Yeah, taking a reading at 15 minutes, cooling and measuring at room temp. Calibrate pH meter every brew. Part of me is maybe thinking that i'll have to back off the Sodium Bicarbonate, and just accept a mash pH of 5.2-5.4 :[

 

[divrack]

Why do you want a 5.5 ph? Genuinely curious to learn, not being sark..

 

[RKi]

Why do you want a 5.5 ph? Genuinely curious to learn, not being sark..

From reading a lot of brewing literature and posts from Martin Brungard etc on here, it's generally accepted that a mash pH of 5.5-5.6 is considered optimal for promoting fullness and malt character in dark beers.

 

[Silver_Is_Money]

It is highly possible that with 4.4 g. of baking soda added to your small batch you may be at or exceeding 5.6 pH. Without measurement, how can you know?

That said, I have full confidence that Martin knows the flavor benefit of mashing at 5.5 to 5.6 when brewing stout darkness beers.

 

[divrack]

From reading a lot of brewing literature and posts from Martin Brungard etc on here, it's generally accepted that a mash pH of 5.5-5.6 is considered optimal for promoting fullness and malt character in dark beers.

I suppose that makes sense given the hardness of dark beer area water...
I tend to cold steep a lot of the dark grains to avoid the harshness of the grain, but that would run counter to the idea of specifically high pH for dark malt flavour. Seems to work ok for me though but it's mainly from an aversion to high tannin in big porter style stuff rather than anything scientifically measured . Just seems to do good beers for me.
Interesting as i understand higher pH extracts more tannin and gives a harsher taste, but maybe that's more relevant a factor in pale beer... I've found I like high ratios of cacl in malty dark stuff and even a good bit of common table salt, notwithstanding anything the textbooks say.

 

[SanPancho]

i also like high chlorides and some sodium in darker stuff. and your levels seem like theyre low enough to not be really significant factors here.

i thought of the unfermentables because of the MO base and the 160 which says sweet to me. but unconverted starches arent necessarily sweet....i dont even know what they would taste like. but the overall idea is that you've got two somewhat opposing tastes here- roast and sweet malt. if one is out of whack it could be outshining the other, which is why i wanted to throw out the idea of not getting full conversion.

 

[ajdelange]

There is always a problem with dark beers in part, at least, because the first generation spreadsheets use linear models which work when the malts DI pHs are close to the target pH's which is where we are with the basemalts and with the lightly kilned color malts used in light beers but not where we are with the darker malts used in dark beers. I ran your numbers through a second generation spreadsheet which does not make that or any of the other assumptions common to the first generation models and found, without any bicarbonate, that your mash pH would fall around 5.42. With 4.4 grams of bicarbonate mash pH would probably be closer to 5.73. Little wonder you are experiencing dull flavors. Now I do need to caveat that the second generation spreadsheets remove the calculation errors from the mash pH estimation process but do not remove errors in malt models. If you feed a good spreadsheet bad data you get bad answers. Whether you get better answers than when using a bad spreadsheet depends on the relative error contributions from malt measurement and computation induced error. I had to make assumptions about what measured malts match the actual malts you are using so there will doubtless be errors but you can take away that adding 4 grams of baking soda to a small mash like this is going to have a pretty large effect. Yes, it is quite likely (but not a certainty - few things in brewing are until the beer is in the glass) that the high bicarb is muting the flavors you seek.

Make a test mash without any baking soda. 5.4 isn't at all a bad pH for stouts despite what the 'experts' say if your roast malt percentage is reasonable. You are at about 16% which is perhaps a bit high.

 

[Silver_Is_Money]

What we critically don't know are your source water analyticals for your mash water. I made some guesses at it, and in the end it appears that I'm in essentially full agreement with Bru'n Water on this one.

If it comes in at a mash pH of 5.00 or a wee smidgen less, be on standby to toss in the 4.4 grams of baking soda.

 

[ajdelange]

Something doesn't compute here. If I'm interpreting the image properly the estimated pH of the mash before any acid or base addition is 4.99. It isn't sufficient to know the DI pH of the malts in order to compute mash pH (we've had this discussion before). You must model the buffering also. This is necessary to compute how many protons are released or absorbed by the malts in shifting from their DI pH's to the target pH. Thus your model implicitly contains malt buffering information in whatever form. If I put your pH numbers and weights into a spreadsheet I must make assumptions about the malt's buffering. I know the linear term for most base malts is about -40 mEq/kg•pH. If I put that value in for all the malts it gives me a pH estimate of about 5.3. To get to 4.99 the colored malts need to be much more acidic than the given DI pH's and buffering of -40 imply. I have to increase buffering to -160 (Sauermalz is a bit less than twice that) for all the dark malts in order to get a pH estimate as low as 5.2. But if I do that the buffering capacity of the whole mash goes up to 208 mEq/pH and it would take 9.4 grams of NaHCO3 to get to pH 5.5.

A much more reasonable model, given no information on malt buffering, is that the first (linear) term is -40 for all the malts as that seems to be a rough average. Using that for each malt the pre- baking soda pH estimate would be 5.38 with a mash buffering of 119. With this model only 1.3 grams of NaHCO3 would be required for a target pH of 5.5. An addition of 4.4 grams would bring the estimated pH to 5.74. These numbers don't differ that much from the 5.42 and 5.73 numbers that I got earlier using actual malt data (i.e. including buffering). This tells us that if we get the DI mash pH right we can get a pretty good estimate but we must have a pretty good estimate of the buffering too. -40 is a pretty good estimate. -160 isn't.

The problem I see here is that evidently the implicit buffering used to estimate the mash pH is much larger than the implicit buffering used to estimate the effects of bicarbonate on it.

 

[Silver_Is_Money]

It will indeed be interesting to see what initial mash pH the OP actually measures for this recipe. I'm up to modifying MME in accordance with actual measured results.

About a year and a half or two ago I seem to recall Martin making an announcement that in accordance with hard mash pH measurement data rolling in from users of his Bru'n Water spreadsheet with respect to its correlation to very dark and robust recipes using loads of roasted malts and caramel/crystal, he dramatically revised Bru'n Water's dark recipe response to said data which was indicating that end users were reporting far more acidic dark recipe mash pH's than his spreadsheet initially (and for many years) had assumed and accommodated. He further announced that this change did not impact lighter recipes. I would value Martin's comment here, confirming (or denying) that I have represented his spreadsheet modification correctly, as it is clearly not my responsibility to express his position here, and I would not want to misrepresent it.

When I transitioned MME to the version 2.xx series I made a similar leap with respect to such robustly dark recipes.

The OP stated that (what I can only assume is a dark recipe revised edition of) Bru'n Water calculated 4.4 grams of baking soda to reach a mash pH of 5.50, and with some minor source water analytical related assumptions applied, so did MME.

If I have made a wrong turn, I can easily revert MME back to a previous engine that predicted far less impact from the malts for robust dark recipes. The last version before I made the 2.xx leap, which is Mash Made Easy version 1.65 (with DI_pH's tweaked slightly up and down the line to 100% match those predicted by version 2.50, and using my same source water assumptions) predicts that this batch will mash (pre-adjustment) at 5.40 pH as opposed to 4.99 pH.

 

[Silver_Is_Money]

Mash Made Easy version 2.50 predicts that a recipe called "Reaper's Mild Stout" will mash (pre-adjustment) at around 4.96 pH. Just recently I seem to recall Martin stating in one of his post responses that he measured quite close to this mash pH when he brewed a batch of Reaper's Mild.

Edit: The link to Martin's mash pH comment for Reaper's Mild Stout is found here: https://www.homebrewtalk.com/forum/...-beer-recipes-mash.652804/page-2#post-8348122

Edit#2: Screenshot of MME version 2.50 and Reaper's Mild Stout:

 

[RKi]

I may make a test mash of this beer as AJ suggested sometime this weekend if i have the time. I'm assuming that this is simply a scaled down version of the recipe i posted above? I'll post the result of course.

For what its worth, when i first began brewing, i had no idea about mash pH and general water chemistry, and i can recall my Stouts tasting better then, than they do now. Although with a twang, likely a slightly lower than optimal final beer pH?

 

[RKi]

Just noticed that i didn't mention the fact that i measured exactly 5.5 mash pH for this beer with a calibrated meter after 15 minutes. That was with the 4.4g baking soda.

 

[Silver_Is_Money]

Just noticed that i didn't mention the fact that i measured exactly 5.5 mash pH for this beer with a calibrated meter after 15 minutes. That was with the 4.4g baking soda.

Presuming that your methods are proper, this seems like a spot on vindication of both Bru'n Water and Mash Made Easy version 2.50 with respect to your batch and its recipe. Thank you!!!

 

[RKi]

I've decided to make a few changes to the original recipe. I'm aiming for a mash pH of 5.4, mainly to reduce the baking soda addition. I've also quite significantly reduced the amount of roasted malts. Looking at a few commercial recipes, the original recipe seemed a bit too aggressive on that front. I also reduced the Oat addition from 12.5% to 10%. I'm hoping that having 70% base malt as opposed to 62% should help diastatic power-wise, and help the beer dry out a little more. I also dropped the IBU's to 35 from 42. Will get this brewed on Sunday hopefully!

HOME BREW RECIPE:
Title: Oatmeal Stout MK VI

Brew Method: All Grain
Style Name: American Stout
Boil Time: 60 min
Batch Size: 12 liters (fermentor volume)
Boil Size: 15.5 liters
Boil Gravity: 1.044
Efficiency: 77% (brew house)


STATS:
Original Gravity: 1.057
Final Gravity: 1.012
ABV (standard): 5.8%
IBU (tinseth): 35.76
SRM (morey): 35.56

FERMENTABLES:
175 g - United Kingdom - Extra Dark Crystal 160L (6%)
290 g - Flaked Oats (10%)
72 g - United Kingdom - Black Patent (2.5%)
175 g - United Kingdom - Brown (6%)
2025 g - United Kingdom - Maris Otter Pale (69.5%)
175 g - United Kingdom - Chocolate (6%)

HOPS:
4 g - Magnum, Type: Pellet, AA: 13.4, Use: Boil for 60 min, IBU: 11.98
15 g - CTZ, Type: Pellet, AA: 14.3, Use: Boil for 15 min, IBU: 23.78

MASH GUIDELINES:
1) Fly Sparge, Temp: 69 C, Time: 60 min, Amount: 11.5 L, 7L
Starting Mash Thickness: 3.83 L/kg

OTHER INGREDIENTS:
0.25 each - Protafloc, Time: 10 min, Type: Fining, Use: Boil
0.6 g - Gypsum, Time: 60 min, Type: Water Agt, Use: Mash
1.5 g - Calcium Chloride, Time: 60 min, Type: Water Agt, Use: Mash
0.36 g - Gypsum, Time: 60 min, Type: Water Agt, Use: Boil
0.91 g - Calcium Chloride, Time: 60 min, Type: Water Agt, Use: Boil
2.76 g - Baking Soda, Time: 60 min, Type: Water Agt, Use: Mash
0.125 tsp - Brewtan B - Pre Mash, Time: 60 min, Type: Other, Use: Other
0.125 tsp - Brewtan B - Sparge, Time: 60 min, Type: Other, Use: Other
0.25 tsp - Brewtan B - Boil, Time: 15 min, Type: Other, Use: Boil

YEAST:
Fermentis / Safale - American Ale Yeast US-05
Starter: No
Form: Dry
Attenuation (avg): 81%
Flocculation: Medium
Optimum Temp: 12.22 - 25 C
Fermentation Temp: 16 C

PRIMING:
Method: Dextrose
CO2 Level: 2.1 Volumes

TARGET WATER PROFILE:
Profile Name: Balanced Profile
Ca2: 68
Mg2: 2
Na: 41
Cl: 95
SO4: 45
HCO3: 174
Water Notes:
1 ml Phosphoric = -0.18 pH
1g Baking Soda = +0.18 pH

Bru'n Water pH 5.49
NOTES:
Aiming for 5.4 mash pH to reduce bicarbonate addition. Significantly reduced Roasted Malt additions and reduced Oats from 12.5 - 10%. Dropped IBU's to 35 too.

 

[ajdelange]

About a year and a half or two ago I seem to recall Martin making an announcement that in accordance with hard mash pH measurement data rolling in from users of his Bru'n Water spreadsheet with respect to its correlation to very dark and robust recipes using loads of roasted malts and caramel/crystal, he dramatically revised Bru'n Water's dark recipe response to said data which was indicating that end users were reporting far more acidic dark recipe mash pH's than his spreadsheet initially (and for many years) had assumed and accommodated. He further announced that this change did not impact lighter recipes....
When I transitioned MME to the version 2.xx series I made a similar leap with respect to such robustly dark recipes.

This is the fundamental problem with the quasi empirical first generation approach. It fits under some circumstances but not other so you patch it to fit those circumstances only to find that the patch raises problems elsewhere. You now have the means at your disposal to get the empiricism out of the algorithms and into the problem of getting reasonable malt data before the user without him having to titrate each malt. That's where the work needs to be done.

 

[ajdelange]

Just noticed that i didn't mention the fact that i measured exactly 5.5 mash pH for this beer with a calibrated meter after 15 minutes. That was with the 4.4g baking soda.

The discussion certainly would have proceeded differently had you mentioned that but it was, nevertheless, interesting.

I've played with the recipe every which way and I cannot get a mash pH prediction of 5.5 with 4.4 grams of bicarbonate no matter what I do within reason. Here's how the data look with 4.4 grams of bicarbonate and the Maris Otter (Malt with arbitrary parameters II) set to have a DI pH of 5.5 so that it has NO proton deficit at pH 5.5 (and it doesn't matter what the buffering is). At the bottom (Row 49) you see the 4.4 grams of Na2CO3 entered and in Row 61 that it produces a proton deficit of 46 mEq. Looking at the individual malt proton deficits (Rows 27 and 37) and their sum in Cell B41 it is clear that this much bicarbonate more than wipes out all the acidity contributed by the dark malts resulting in a mash proton deficit of 16 mEq. at pH 5.5. The graph shows the deficits at other pH's and as it crosses 0 at pH 5.62 (also see Cell B15) that is the estimated pH for this mash.

Now this is a new spreadsheet and so there may be a glaring error in it but all the numbers look reasonable but something just does not compute here. Therefore I suspect your pH reading even though you followed proper calibration procedures. I can't be sure, of course, that there was a problem with it. Maybe your Maris Otter has a DI pH of 5.28 (what it would take to get pH 5.5 with 4.4 grams of bicarbonate) but I doubt it. Maybe some of the other grains were much more acidic etc.

I've decided to make a few changes to the original recipe. I'm aiming for a mash pH of 5.4, mainly to reduce the baking soda addition.

Keep in mind that at pH 5.5 only 12% at most of the bicarbonate you add will be gone so it isn't the bicarbonate that was responsible for muting the flavors you sought. What mutes flavors is high pH in the mash and I am still suspicious that this may have been what's responsible. A test mash is a good idea.

I've also quite significantly reduced the amount of roasted malts. Looking at a few commercial recipes, the original recipe seemed a bit too aggressive on that front.

That's probably a good idea too.

 

[Silver_Is_Money]

I worked on some tentative revisions to 'Mash Made Easy' last night and this morning, and tentatively the output of my revisions when applied to the OP's initial recipe are as seen below. This tentative revision shows a need for only 2.73 grams of baking soda to hit a mash pH of 5.50, and with the OP's 4.40 grams of baking soda it indicates a mash pH of 5.68. Lastly, to hit a mash pH of 5.40 the new/tentative version predicts a need for only 1.85 grams of baking soda. I'll kick the tires on this one for awhile, plus I'm planning to brew an Oatmeal Stout soon which is intentionally a bit top heavy in dark roasted malts, and I will use this tentative 2.60 revision for that batch to see how its measured mash pH at the 20 minute mark stacks up to the prediction of released version 2.50. That version 2.50 hit the OP's real world experience spot on makes me a bit skeptical as to this 2.60 revision, which is admittedly a compromise between A.J.'s solution (which indicates that the OP's 1st recipe will mash straight up at a pH of 5.42 with no adjustments required at all) and the version 2.50 solution to the OP's original recipe, which said to add 4.4 grams of baking soda. Somehow I intuitively can't believe that this recipe will mash straight up at a pH of 5.42 with no need for adjustment. But I also clearly realize that intuition makes for seriously bad science.

 

[ajdelange]

Somehow I intuitively can't believe that this recipe will mash straight up at a pH of 5.42 with no need for adjustment. But I also clearly realize that intuition makes for seriously bad science.

Every good scientist is guided by his intuitions. But "guided" is the key word. As Edison said its 2% inspiration and 98% perspiration. If you feel intuitively that this mash shouldn't come up at 5.42 then try to figure out how my (or your new) algorithm got us there. The "voltmeter/toubleshooter" spreadsheet, which you have and will be getting a new copy of very shortly, will let you do that - that's what it was originally intended for i.e. to give developers insight into what their products are doing. You are getting a new version because in going over this again I found some problems with it which I fixed but I also put in Riffe's model of Brown malt (with a stab at its buffering) and his model for flakes oats. This reduces the no bicarb estimated pH from 5.42 to 5.38. To get things to pH 5.5 now takes 1.85 grams of NaHCO3. With 4.4 grams the predicted pH is 5.66. To pH 5.5 that much (4.4g) bicarb absorbs 46.3 mEq of protons and I still can't find the protons in the specified malts to cover that. I've also filled a bit of unused real estate under the graph with a summary of the selcted malt's DI pH's, buffering parameters and the amount each swings the pH of the mash. This may be useful in spotting something.

 

[ajdelange]

Just remembered that you can't run VBA's (did I remember that right?) so here's how things look without any bicarb. You can see the proton deficits for the water (none), for each of the malts, for the effects of the added salts. You can also see the effects on the mash pH of each of these relative to the predicted pH of 5.38. For example the second malt selection, 150 L Crystal is seen (color shaded area) to have a pH lowering effect of 0.07. If you took that malt out the pH of the estimate would rise by about 0.07 and if you doubled the amount of that malt you would see a decrease in the estimated pH of about 0.07. However you estimate pH you must have some means of determining what the effects of the individual malts are on the final answer. Perhaps you could check those against what we show here. At this point it isn't a question of who has the better model or algorithm but of trying to find inconsistencies between our approaches. This would, I think, be of benefit to at least one and perhaps both of us.

You will also find displayed here the DI mash pH's for each malt (Col J). The differences between what you have and what I have represent differences in the way we represent the malts he is using. You could try altering your pHDIs (I still have no idea how you handle buffering) to see if that brings closer agreement. I can, of course, do the same thing. I note that your flaked oats DI pH is close to the value I measured for flaked barley. Riffe finds flaked oats appreciably more basic than this. I'm using his numbers. That raises my pH estimate to 5.38 from the 5.31 value I get with barley.

 

[Silver_Is_Money]

Thanks A.J.! I did receive your latest spreadsheet, but unfortunately LibreOffice 6 running in Linux can't handle the VBA code. It kicks up error after error, and I actually had to kill LibreOffice Calc in order to exit it. Your spreadsheet is clearly an Excel only proposition, so it may take me awhile before I ever see it running.

Edit: We were both typing at the same time... Thanks for posting the above!!!

 

[Silver_Is_Money]

The reason why my intuition is stuck in disbelief mode is because I've been brewing since the 80's, and I've been doing all grain since the early 90's, and all I ever heard for decades was that the likes of robust Stouts and Porters need 100-150 ppm alkalinity (or more). Even Kai supported this. And John Palmer's various calculators used to point to the range of 250 ppm alkalinity (or perhaps higher) for truly robust stouts. And even you rather recently mentioned that your dry stout recipe from the past required (from memory) give or take a ballpark of 75 ppm alkalinity.

Now to see all of that turned completely upside down is rather hard to fathom. Were people mashing Porters and Stouts at pH 5.7 - 5.8(ish) for decades? Why didn't anyone ever toss up a red flag?

 

[ajdelange]

Were people mashing Porters and Stout at pH 5.7 - 5.8(ish) for decades? Didn't anyone ever toss up a red flag?

Yes. They were! And yes I did and no, it was not well received at first nor until the good but inexpensive pH meters came along and people started measuring. Discovering this was one of the biggest "Omigosh" moments of my brewing life. Go back to those days of Palmers nomograms. Tablespoonsfull of chalk were called for in dark recipes (and I added them in at least one case I can remember because all the books and articles said I should). That was before I started measuring.

Now to see all of that turned completely upside down is rather hard to fathom.

It has been accepted at various times that the earth was flat and that it was at the center of the universe. There are similar "momilies" as they used to be called in the old HomeBrew Digest (for what reason I never understood) concerning brewing. Were you to ask me "What did you ever do for home brewing?" my first answer would be "I got people to quit throwing un-necessary chalk and bicarbonate into dark beers."

Now maybe i'm all wrong about this but
1)The science says it should be this way (little or no alkalinity for mild stouts)
2)The lab work I've done says it should be this way
3)The mild stouts I've brewed confirm that it should be this way.

 

[Silver_Is_Money]

What is to be made of the reports from people who have measured Porter and Stout mashes in the range of 4.9 to 5.0 pH?

Would not an approximately 5.5 gallons (to the fermenter) size batch that measures within this pH range and weighs in at ballpark 11-13 Plato need ballpark about a TSP of baking soda? (which from various sources would weigh from 4.4 to 4.9 grams)

And what to make of the OP, who claims to have hit 5.5 pH on the nose after adding 4.4 grams of baking soda? Plus (over on my "What is the most Baking Soda you ever added.." thread) forum member dmtaylor recently posted that he has measured Stouts that mashed at as low as 4.8 to 4.9 pH, and Martin recently stated that by his personal measurement Reaper's Stout (not too insanely loaded with roasted malts) mashes at ~4.9 pH.

 

[Silver_Is_Money]

I don't yet know where the truth in this will fall, but it strikes me as a potentially good fit to early 1800's German Philosopher Arthur Schopenhauer, who critically observed that:

All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident.

 

[mabrungard]

Were you to ask me "What did you ever do for home brewing?" my first answer would be "I got people to quit throwing un-necessary chalk and bicarbonate into dark beers."

Thankfully, there is plenty that you've done. But I question that your admonition to stop adding chalk really had much effect since only a small portion of the chalk actually dissolved and reacted with the weak acids in a mash. My experience is that brewers trying to avoid an excessive pH drop had little success with chalk. My data and Kai's data point to a result that shows that the best you can achieve with even a massive chalk addition was around 0.1 unit increase.

While some stouts and porters don't have to be brewed with high alkalinity mashing water, most do benefit from the resulting elevated wort pH produced by water that does have readily-available alkalinity.

 

[ajdelange]

What is to be made of the reports from people who have measured Porter and Stout mashes in the range of 4.9 to 5.0 pH?

What can I say. I wasn't there. All I can say is that their experience is different than mine has been and try to figure out why the discrepancy. Often, if it is found, it is a bad pH reading.

Would not an approximately 5.5 gallons (to the fermenter) size batch that measures within this pH range and weighs in at ballpark 11-13 Plato need ballpark about a TSP of baking soda? (which from various sources would weigh from 4.4 to 4.9 grams)

That's going to depend.

When I did Irish stout I always used 10% roast barley, 10% flaked barley and the rest Maris Otter. When I put those numbers into the new spreadsheet with water of alkalinity 70 (which is where my water usually falls but it can go higher or lower) with a mash thickness of 1.27 qts/lb with water with calcium hardness of 60 and magnesium hardness of 50 it predicts pH of 5.59. I always got right around that in the mash tun which would cause me to post statements to the effect that perhaps some stout brewers should be thinking about adding acid rather than alkali. This, of course, was not well received but then reports started coming in from other brewers who were seeing the same results.

Now we should keep in mind that the parameters of the malts I used in the prediction spreadsheet were measured by me on the malts I was using so naturally I got good results.

Using the numbers above no, a stout with those numbers does not need bout a tsp of baking soda. In fact, if you want a pH like 5.5 or 5.4 you are going to need acid - not base. Now if you increase the roast barley to 20% of the grist and want pH 5.5 you are going to need some bicarbonate. Assuming that you are mashing at the 1.27 thickness with 3.5 gal DI water with enough CaCl2 in it to get you about 50 mg/L Ca++ you would need about 2.1 grams (2/5 tsp?). Increase the roast barley again to 30% of the grist (ick, but I'll bet someone has done it) and now you are going to need about 6.2 g sodium bicarbonate.

And what to make of the OP, who claims to have hit 5.5 pH on the nose after adding 4.4 grams of baking soda?

Again, I don't know what to say other than to observe that unless the malts he is using are substantially more acidic than the malts I know of that I have assumed to be similar or unless the sodium bicarbonate he is using has been adulturated with some neutral substance that isn't possible. Whenever someone who has used a spreadsheet gets a pH reading that is right on the nose I know immediately that the reading is probably not a good one because that just doesn't happen (but you'd be amazed at how many people report that Brun water always predicts mash pH to 0.01). So in this particular case, as I always do when something is fishy, suspect the pH reading as it so often turns out to be the case. I've certainly been led down the garden path by faulty pH readings. It took me quite a while to master the art of using a pH meter. I don't see why it shouldn't take others some time too. But I can't say it is a faulty pH reading because I just don't know. If the pH reading is good then we have to find a lot of acid somewhere to balance that 4.4 grams of bicarbonate,

Plus (over on my "What is the most Baking Soda you ever added.." thread) forum member dmtaylor recently posted that he has measured Stouts that mashed at as low as 4.8 to 4.9 pH, and Martin recently stated that by his personal measurement Reaper's Stout (not too insanely loaded with roasted malts) mashes at ~4.9 pH.[/QUOTE]Again I have no idea what to say other than that there is an explanation. I don't know what it is. Perhaps they had 30% roast barley. Perhaps they screwed up a pH measurement. Perhaps their dark malts are appreciably more acidic than anything I or Kai or Joe Walts have ever measured.

There is no question that one can formulate grists that will require bicarbonate (or other alkali) in order to hit mash pH and there is this "mommily" going around that stouts taste better if mashed at higher pH. So if people are shooting for 5.6 or even higher and using high percentages of highly acidic malts they are going to need bicarbonate.

 

[ajdelange]

Thankfully, there is plenty that you've done. But I question that your admonition to stop adding chalk really had much effect

I was not nominating my self for an award here.

...since only a small portion of the chalk actually dissolved and reacted with the weak acids in a mash.

And then what happens to the rest? Depending on how fine the crystals are some will doubtless be filtered out by the lauter bed but the rest will make it through into the boil where, slow though the reaction may be, it will continue to absorb protons thus raising kettle pH. That which doesn't react in the kettle will pass on to the fermenter where, slow though the reaction may be, it will absorb protons secreted by the yeast for the purpose of establishing the pH they like. This makes them work harder at acid production than they other wise would have to. Less energy available for making beer. Finally, evidently, some gets carried over into the finished product as I've had people report beer that "tastes like a chalk board" back in the days before we got smart about chalk. So the significance of getting rid of chalk is perhaps greater than you were aware of. Plus, it's not only chalk that I tried to dissuade people from using - it was alkali in general. Most stouts and porters do not require alkalinity. When it is used mash pH goes high and beer flavors are muted. That's true in a stout just as it is in any other beer.

My experience is that brewers trying to avoid an excessive pH drop had little success with chalk. My data and Kai's data point to a result that shows that the best you can achieve with even a massive chalk addition was around 0.1 unit increase.

How far you can go depends on how much chalk you add. There is no fundamental limit on the possible pH increase. It is a question of how long you are willing to wait to get it. I have reported here that I have found the reaction between chalk and acid (strong acid too - it doesn't have anything to do with the acid strength AFAIK) carrying on for more than 24 hours.

While some stouts and porters don't have to be brewed with high alkalinity mashing water, most do benefit from the resulting elevated wort pH produced by water that does have readily-available alkalinity.

Not sure what you mean by "readily available" alkalinity. No actually, I think I do. Bicarbonate alkalinity is readily available becuase it reacts fast. Chalk alkalinity is not readily available because it takes forever to react. BTW I shout mention that I don't thing its the reaction of chalk that is so slow. I think it is the dissolution. If one were to dissolve it in sulfuric acid, for example, I'm sure it would be "readily available". Interesting thought. Put some chalk in a beaker, add some water, add sulfuric (or hydrochloric or lactic...) acid. Let the acid dissolve the bicarbonate and let the mixture stand long enough for the disolution to complete. Make up to volume and bottle. You now have a solution of calcium ions, bicarbonate ions and sulfate (or the anion of whatever acid you used). Have to think about that one.