I'm doing an AG porter recipe. Historically, I have been dissatisfied with my porters - they come out thin, and a bit acidic. Some research suggested that my issue may be mash pH, so I bought so pH strips and some chalk. I measured my mash pH using the strips and it was in the 4.9 range, so I started adding chalk 1 teaspoon at a time. Eventually I got to 5 teaspoons, and the pH strip still registered about 5.0, MAYBE 5.1, but it is hard to tell with the colors. I decided to err on the side of caution and stop adding stuff to my mash.

I eventually had to also add 1.5 gallons of boiling water to hit my mash temp. So, I went from 4.25 gallons of water to 5.75 for a 13.6lb grain bill.

My question is - did I add ridiculously too much chalk? If so, what are the negative side effects of having done so?

For future brew sessions I think I will purchase a digital pH meter, but for this batch in particular I would like to know if I am fubar or not.


According to my town's water report (from 2014....) here's what's in my water:

  • 33 ppm Sodium
  • 0.03 ppm manganese
  • 0.44 ppm chlorine (relavent?)
  • 3.03 ppm chloramines (good thing I filtered my water...no wait, that only helps with chlorine...)
  • 0.11 ppm copper
  • 34 ppm sulfate

I think that should be all the relevant stuff.

  • You need a report with your alkalinity. What you reported here doesn't include calcium or magnesium or carbonate. These are the things to be concerned with for pH issues.
    – brewchez
    Jan 31 '16 at 23:51
  • drat. suppose I shall have to pay for a more detailed report then.
    – wesanyer
    Jan 31 '16 at 23:52
  • Unfortunately you may be right. Not all municipalities publish very good reports. If you haven't heard of them, Ward Labs offers reasonable rates on testing a water sample. I've used their mail in service a couple times and been happy with the results.
    – brewchez
    Feb 1 '16 at 0:06

It's impossible to say without knowing the recipe, and your existing water etc.. It could go either way, but I'd be inclined to say you'll be fine. It does sound more than we'd typically add to a 5 gallon batch, but I don't see what negative affects it will have, and it clearly did raise the pH over time which was the intent.

To put some numbers to it, 5 level teaspoons in a 5 gallon batch will add ca. 200ppm Calcium and 300ppm carbonate [source]. Both within what's considered reasonable amounts, but of course we don't know the final amount without knowing your water profile.

It's better to ask this question after you've tasted the packaged beer to see if any positive or negative contribution can be attributed to the chalk additions.

  • Fair point. I will reassess after the beer ferments. I do not have a water report, but I will look for one on my town's website.
    – wesanyer
    Jan 31 '16 at 22:33
  • see my original post for the water info.
    – wesanyer
    Jan 31 '16 at 22:49

In addition to what mdma stated.

High ppm of calcium could give the finished beer a "mineral water" flavor, but this is appropriate in many styles.

You may want to consider RO or distilled bottled water at least 50/50 with your filtered water. This will help with the pH and cut down on the Chloramine.


I'm doing an AG porter recipe. Historically, I have been dissatisfied with my porters - they come out thin...

The answer to thin, as in mouth-feel, is normally in your malt bill, the yeast you choose and your mash thickness and temps. See here. Mash ph also plays a role, but it isn't the only contributing factor, and the ph is affected by the other factors.

and a bit acidic

Acidity is higher when you mash your roasted malts. You can steep them apart from your mash or even steep them cold and never boil them, since

the burnt and acrid components derived from mashing dark grains usually occur due to prolonged periods of contact with hot water.

Source, recommendations and cold steeping

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