Detroit water - Additions for stout

Typically I find that my lighter beers come out better than dark. I want to brew a stout for St. Patrick's day so have been toying around with the idea of water additions. I've read through the primer and am starting to develop a general understanding, however I have a ways to go still.

My recipe will be pretty simple - 65% Maris Otter, 25% Flaked Barley, 10% Roasted Barley

Any suggestions for water treatments? Here is my water analysis:

All units are mg/L unless specified otherwise

Turbidity (NTU) 0.07
Aluminum <0.050
Iron <0.050
Copper <0.005
Magnesium 7.47
Calcium 25.0
Sodium 4.79
Potassium 0.94
Manganese <0.002
Zinc <0.1
Silica 1.0
Sulfate 31.2
Chloride 9.0
Phosphorus 0.28
Free Carbon Dioxide 3.5
Total Hardness 105
Total Alkalinity 89
Carbonate Alkalinity 0
Bi-Carbonate Alkalinity 89
Non-Carbonate Hardness 16
Chemical Oxygen Demand 11.6
Dissolved Oxygen 10.2
Ammonia Nitrogen (NH3-N) 0.2
Organic Nitrogen 0.4
Nitrite Nitrogen (NO2-N) <0.1
Nitrate Nitrogen (NO3-N) 0.36
pH 7.71
Specific Conductance @ 25C (micromhos) 226
Temperature (C) 22.6

Believe it or not you may need to add some acid. When I brew that recipe with water less alkaline than yours and with similar calcium content I get mash pH from 5.55 to 5.62. I really feel strange advising people that they need acid in a stout and I usually omit it and just live with 5.5 but if it goes over 5.6 I do add acid. The problem is that I can't tell you exactly how much to add. That really should be determined experimentally with a good pH meter in hand. One approach could be for you to rely on the 0.1pH/% rule of thumb for sauermalz and add that. This should be safe as presumably you'd fall in the 5.4 - 5.5 range. Another thought is to try to beat it through reduced alkalinity i.e. dilute your water 2:1 with RO which would get the alkalinity down to about 30. That level usually gets me 5.55 with this recipe. If you do go this route add some calcium chloride (or sulfate if you want to boost the hops) to get the calcium level back up).

I'm not too sure what the truth is here. The water report has some sort of error(s).

The Ca and Mg concentrations do not produce 105 ppm hardness. The Ca would need to be more like 30 ppm for that.

The reported alkalinity of 89 ppm (I assume as CaCO3) equates to 107 ppm HCO3. That much HCO3 throws the ionic balance off even further. So, I'm confused by the report.

In any case, my analysis does not suggest that any form of acid will be needed. That water with 30 ppm Ca and 89 ppm HCO3 (assumed) would produce a mash in the 5.3 range. This assumes that a little CaCL2 is added to bring the Ca up to about 50 ppm. If anything, a teeny bit of alkalinity is needed to help bring the mash to about 5.4.

Pick your poison, but I'd wager that adding acid will make your stout worse since there is no way that the mash pH was too high previously.

Thanks for both of your responses. It sounds like my best course of action is to just buy and calibrate a pH meter rather than trying to guess if the water analysis is accurate.

mabrungard - I used your spreadsheet with an older report (from June, 2011) and the ions seemed more balanced. The values do not seem drastically different from the one I pasted earlier (September, 2011), but I'm guessing small differences can cause big errors. Here are the values from the 2 reports. The numbers on the left are the ones I posed earlier and the ones on the right are from a slightly older report. Both reports are signed off by a "sr. analytical chemist" and "principal chemist" for the water treatment plant, but perhaps they are just rubber stamps.


Turbidity (NTU) 0.07 0.12
Aluminum <0.050 0.121
Iron <0.050 <0.050
Copper <0.005 <0.005
Magnesium 7.47 7.56
Calcium 25.0 25.5
Sodium 4.79 4.97
Potassium 0.94 0.90
Manganese <0.002 0.002
Zinc <0.1 <0.1
Silica 1.0 0.8
Sulfate 31.2 31.2
Chloride 9.0 9.0
Phosphorus 0.28 0.33
Free Carbon Dioxide 3.5 4.4
Total Hardness 105 105
Total Alkalinity 89 79
Carbonate Alkalinity 0 0
Bi-Carbonate Alkalinity 89 79
Non-Carbonate Hardness 16 26
Chemical Oxygen Demand 11.6 22.8
Dissolved Oxygen 10.2 11.0
Nitrite N2 (NO2-N) <0.1 <0.1
Nitrate N2 (NO3-N) 0.36 0.37
pH 7.71 7.55

mabrungard said:

I'm not too sure what the truth is here. The water report has some sort of error(s).

Click to expand...

There may in fact be no errors at all (though, of course, there most probably are). The fact that the report does not balance does not mean it is in error. It means that it does not represent the result of analysis of a single sample or of a uniformly sampled ensemble of samples. Those numbers represent averages over some period of time (I assume 1 month). If the lab took every sample and analyzed it for all ions and averaged those then the report should balance more closely that it does. But most suppliers don't do that. They measure different parameters at different times and with different frequency. This can easily lead to an imbalance of the averages. You can easily convince yourself of this with a little Monte Carlo gaming on the computer. On top of which there may be errors in their procedures.

We can't calculate bicarbonate because we don't know what the end point of the titration used in its determination was (though this isn't a big swinger i.e. I can't appreciably improve the balance by fiddling with the alkalinity defining end point pH).

mabrungard said:

The Ca and Mg concentrations do not produce 105 ppm hardness. The Ca would need to be more like 30 ppm for that.

Click to expand...

Total hardness is often measured by titration with a chelating agent whereas metals are often measured by AAS. The usual chelating agent (EDTA) will grab most metals and thus the total hardness can be greater than the sum of the calcium and magnesium. Strontium, in particular, can occur in fairly high concentration in some waters in the US. I have no idea as to whether this is what is responsible here but offer it as a possibilty.

mabrungard said:

So, I'm confused by the report.

Click to expand...

I'm a bit surprised at that. I've seen lots and lots of water reports and these aren't noticeably bad relative to my recollections.

mabrungard said:

In any case, my analysis does not suggest that any form of acid will be needed.

Click to expand...

I'm reminded of an occasion on which I was briefing some conference and a young AF Lt. stood up and stated that her model showed that the performance data (taken from the actual system) I was presenting was not possible. She asked how I would explain that. The explanation was pretty simple. Hard data always trumps an analysis (provided it is carefully collected and quality checked).

If OP manages to buy MO which is more acid than any I've ever seen, flaked barley that is more acid than I've ever seen and roast barley that is more acid that I've ever seen, and I mean more acid by an fair amount, then he might need alkali but I've done this recipe enough to know that the odds are very small. His probability of hurting himself by adding acid is much, much smaller than his probability of hurting himself by adding alkali which I'd put at over 95%. But we are dealing with probabilities and the best way to rid ones self of the associated uncertainty is a pH meter.

I'm very interested in seeing how this works out for you...especially since I live in Westland.

I have a brand new pH meter and controls that i would be happy to let you borrow if I could watch some of your mash process. I am getting ready to do my first all-grain, and would jump at the opportunity to see a typical mash before getting my feet wet.

Let me know I f you would be open to having a guest watch your mash and use my pH meter.

Being another person using Detroit city water I can tell you for a fact that if you don't increase the residual alkalinity you will not get the beer you want. Every stout or porter I made before learning some about water chemistry turned out almost sour. I would however recommend that you not go as far as the calculators or books say to. Maybe add 75% of the recommended salts.

I'll agree that the water data is not terrible, but there are inconsistencies that aren't going to go away. There are errors of some form there. The good thing is that the errors amount to 10 or 20 ppm one way or the other and the net effect is somewhat small.

I appreciate the value of hard data and I suggest that the fair lieutenant in this case remember that the OP pointed out that their light colored beers came out fine and the dark ones failed to impress. That would hardly suggest that excessive alkalinity was at play here.

E-Mursed said:

Let me know I f you would be open to having a guest watch your mash and use my pH meter.

Click to expand...

PM sent

dannypo said:

Being another person using Detroit city water I can tell you for a fact that if you don't increase the residual alkalinity you will not get the beer you want.

Click to expand...

How do you know what he wants?

dannypo said:

Every stout or porter I made before learning some about water chemistry turned out almost sour.

Click to expand...

That's the way stout is supposed to be or at least a dry stout which is what OP's recipe is for

From the BJCP Guidelines: "Moderate roasted, grainy sharpness, optionally with light to
moderate acidic/sourness, and medium to high hop bitterness. Dry,
coffee-like finish from roasted grains."

I know that's the way I like it (think Guiness - a world class beer IMO) and was starting to think I was losing my marbles so that's why I looked it up.


Curious as to what mash pH you are getting. Most people prefer beers made with mash pH 5.4 - 5.5. They feel the "flavors are brigher". But de gustibus non est diputandem . If you like beers brewed in a higher pH range better then brew by all means brew them that way.

ajdelange said:

Curious as to what mash pH you are getting. Most people prefer beers made with mash pH 5.4 - 5.5.

Click to expand...

Just curious as to why I always hear 5.2 as the gold standard for pH? Is this just a minimum value that shouldn't be crossed? Despite it apparently not working quite often why does 5 Star attempt to lock in pH at 5.2? Do different styles require different pH?

Secondly, when using a meter how long does it take for a mash to get to its pH level? That is should it be checked to determine if acid malt or salts need to be added to optimize pH?

mabrungard said:

...that their light colored beers came out fine and the dark ones failed to impress. That would hardly suggest that excessive alkalinity was at play here.

Click to expand...

We don't know how much better his light colored beers could be if he controlled the pH for them too. He is implying that he does not do that. He can brew light beers with the water he has but I can promise him improvement if he uses some acid. It's in the light, delicate beers that it really pays off.

But given #7 and #10 I think we should go back to OP and ask why he didn't like his stouts and what does he want them to be like. Is it like the BJCP description or does he not like the traditional flavor?

ajdelange said:

But given #7 and #10 I think we should go back to OP and ask why he didn't like his stouts and what does he want them to be like. Is it like the BJCP description or does he not like the traditional flavor?

Click to expand...

As I reflect on it a bit I realize that stout failures were early in my all grain days. I fermented too warm, didn't make liquid yeast starters, rehydrate dry yeast, etc. It is quite possible that my improved technique and experience will help a bit. Flavor wise I recall a slight almost metallic taste, but I could be describing that poorly. Recently I have had good success with belgians and pale ales, but perhaps the true independent variable is my process and not my water.

mcberry said:

Just curious as to why I always hear 5.2 as the gold standard for pH?Is this just a minimum value that shouldn't be crossed?

Click to expand...

Brewing is a very complicated process in which there are so many things to remember that people need to have benchmarks. There is no ideal pH - the values we choose represent compromises between things like protein degradation, starch conversion, hops utilization, good kettle break etc. The oft cited 5.4 - 5.6 range, measured at room temperature, seems to produce beers that most people like. Since mash pH falls back about 0.005 unit per degree C at 60 °C (140) that 5.4 - 5.6 range would correspond to 5.2 - 5.4 and that's where I think the 5.2 comes from.

mcberry said:

Despite it apparently not working quite often why does 5 Star attempt to lock in pH at 5.2?

Click to expand...

I think that's simply because most people have heard that 5.2 is the optimum pH IOW it's marketing.

mcberry said:

Do different styles require different pH?

Click to expand...

I say "no" because I think the 5.4 - 5.6 represents a good compromise. But if you look at the British literature and the German literature I think you'll see that the Germans tend to stay at the higher end of that range and the Brits at the lower. I'm always advocating varying things to see if it improves your beer and pH is no exception.

As #7 and my response in #10 suggest tastes are variable. Some people might not like beers brewed with "proper" pH. That's the great thing about home brewing. You can brew it any way you like.

mcberry said:

Secondly, when using a meter how long does it take for a mash to get to its pH level? That is should it be checked to determine if acid malt or salts need to be added to optimize pH?

Click to expand...

That depends on what form the acid is in. With bottled mineral or organic acid the pH stabilizes quite quickly. If sauermalz (acidified malt) is used it can take quite a while.

After you have endured paying for a meter and have calibrated it it takes very little effort to make a reading. For that reason I advocate frequent readings throughout (and beyond) the brew day. At dough in, 15, 20, 25 minutes thereafter if sauermalz is used, at the end of every temperature step, at the beginning and end of the boil (or in the fermenter), 12 hours after pitching, and final packaged beer pH should all be recorded. If you have these pH "milestones" recorded they can be of great value in helping you to assess how subsequent batches of the same beer are going.

ajdelange said:

From the BJCP Guidelines: "Moderate roasted, grainy sharpness, optionally with light to
moderate acidic/sourness, and medium to high hop bitterness. Dry,
coffee-like finish from roasted grains."

I know that's the way I like it (think Guiness - a world class beer IMO) and was starting to think I was losing my marbles so that's why I looked it up.

Click to expand...

Use caution here. Guinness Dry Stout is post acidified with an addition of soured beer. This has been confirmed and reported by Charlie Papazian a few years ago.

As far as I know, Guinness targets a relatively normal mash pH range as AJ has highlighted. Allowing the mash pH to drop into the 5.2 range or lower increases the fermentability of the wort and reduces body, so avoid an acidic grist to send your mash pH too low.