Water for dark beers

[narvin]

I've recently changed my thinking on water for dark beers.  I knew that Kai's experiments have shown that roasted malts don't contribute as much acidity per SRM as crystal malts, and I've also lowered my target mash pH to 5.4-5.5 (@20C) as alkalinity/high pH are a major culprit in lifeless beer, extracting tannis and astringency, and other bad things. But AJ DeLange's posts (for example, here) made me consider the possibility that I don't need any chalk in my water despite it's relatively low alkalinity.

I recently made a 40 SRM oatmeal stout with 2.5 pounds of roasted barley in the mash for a 12 gallon batch. Despite an alkalinity of only 48 (and RA of 25) in my tap water, I added no chalk or other carbonates. My mash pH was 5.5, and I wouldn't want it any higher.

One side note is that ColorPhast pH strips were almost unreadable in the dark wort, but looked like they read much lower than the meter. If I had to guess, the strips read around 4.8. With the error, that's still 5.1.  The meter was just calibrated. I'm starting to question whether the ColorPhast strips are really worth using.

[richardt]

Interesting points.  Most importantly, how does the beer taste?

[mabrungard]

If you were using a beer color-based estimate for what your residual alkalinity needed to be (like Palmer), then you were probably overdosing with alkalinity.  Bru'n Water was created based on Troester's experiments and it does account for the limited acidity of roast grain.  Roast grain does have less acidity than Crystal malts when compared on a grain color basis. 

There was no mention of any crystal malts in the stout above, but its very possible that the tap water was well suited for this beer with respect to the grain bill.  Bru'n Water lets a brewer test the effect of their grain bill with their amended brewing water to assess if further amendment is needed to produce an acceptable mash pH.

As I recall, work by both AJ and Kai have indicated that pH strips typically read about 0.3 units too low when compared to the result of a calibrated pH meter on a sample measured at room temperature.  I cannot recommend pH strips as a preferred measurement in mashing due to the measurement error and the effect of wort color on the reading.

[tom]

And if I recall correctly, AJ only brews light lagers, so that is where his experience lies.

[James Lorden]

as alkalinity/high pH are a major culprit in lifeless beer, extracting tannis and astringency, and other bad things.

Generally speaking, I have not ever seen a real correlation between mash pH and final beer pH.  There is too much going on during fermentation in my mind to allow for a good rule of thumb.

That said, I agree whith your assesment on high pH having an adverse affect on beer flavor and last year did an experiment where I dosed individual bottles of finished beer with phosphoric acid until the pH was towards the lower end then entered those beers into competition along with the undoctored versions.  I along with the judges appreciated the beers with the lower pH a bit more - like putting lemon juice on vegetables, it made all the other flavors pop... Obviously not a big enough sample to apply to anything other then those specific beers that I had entered.

[johnf]

And if I recall correctly, AJ only brews light lagers, so that is where his experience lies.

He brews dark lagers and stout regularly. He has brewed other kinds of beer (Gordon Strong's book references his well known experiments with authentic vs soft water for English Pale Ales, for example).

[narvin]

Interesting points.  Most importantly, how does the beer taste?

I'll let you know in a week or two.  The wort tasted great 

[Al Equihua]

is there a real diference in tasting a beer with a very low or high diference in Ph? i mean.. if i hit 5.9 or lets say 5.1...
im a little confused about that, need to read a lot

[malzig]

I recently made a 40 SRM oatmeal stout with 2.5 pounds of roasted barley in the mash for a 12 gallon batch. Despite an alkalinity of only 48 (and RA of 25) in my tap water, I added no chalk or other carbonates. My mash pH was 5.5, and I wouldn't want it any higher.

One side note is that ColorPhast pH strips were almost unreadable in the dark wort, but looked like they read much lower than the meter. If I had to guess, the strips read around 4.8. With the error, that's still 5.1.  The meter was just calibrated. I'm starting to question whether the ColorPhast strips are really worth using.

You can rinse the pH strip off with water before reading it.  It makes reading a dark beer's pH much easier.

[mabrungard]

is there a real diference in tasting a beer with a very low or high diference in Ph? i mean.. if i hit 5.9 or lets say 5.1...
im a little confused about that, need to read a lot

There is a substantial difference in the beer flavor and mouthfeel in a pH difference that large.  At high pH, the flavor is typically characterized as dull and the mouthfeel is relatively unaffected.  At the typical target pH range around 5.4, the flavor is crisp and the mouthfeel is still relatively unaffected.  At low pH, the flavor is typically characterized as tart and the mouthfeel is typically thinned and the beer may be overattenuated.

Try and aim for that middle pH of about 5.4 and the results will be better.
 

[Kit B]

You can rinse the pH strip off with water before reading it.  It makes reading a dark beer's pH much easier.

WHAT!?
Doesn't this contaminate the strip & make it start reading toward the water pH?

In my experience, most types of pH strips are somewhat unreliable.
The largest reason I've found is contamination.
I even found that 2 stores in my area are currently selling contaminated strips.
I refuse to use them, any longer...
Bought a $25 groupon & picked up a pH meter for less than half the retail price.

[tschmidlin]

Bought a $25 groupon & picked up a pH meter for less than half the retail price.

You saw pH meters on groupon?

[Kit B]

No...local homebrew store was selling a coupon for $50 of merchandise for $25.
They didn't have the meter I wanted in stock, so they sold me an upgraded meter at a discounted rate...
$70 meter discounted to $50.
I paid $25 + tax, for a $70 meter.

[tschmidlin]

Nice score

[malzig]

WHAT!?
Doesn't this contaminate the strip & make it start reading toward the water pH?

No, rinsing the strip shouldn't change the pH reading.  I believe it is in the instructions for the ColorpHast strips, iirc, I'll look it up.