I have done many many brews with untreated local tap water, and I have only 3 times had an issue with chlorophenols. I now treat the tap water with 1 campden tablet/100l/20gl. But, revieing my records it looks like it was only pale ales that were affected.

This leads me to question do darker ales in some way buffer the chlorophenols?

Is there something in dark or aromatic malts that reduces chlorophenol generation?

Is it just when it happens they mask the flavour?

Or is this just random chance and it affects all ales the same but I just happen to have been affected on 3 pales?


1) Dark malts and residual sugars definitely help mask the offending phenol. But not completely, coffee from tap water is the best example. In black coffee chloraphenol is pretty easy to detect, but add some cream and sugar and it becomes bareable.

2) This is only speculation. I think it's possible that your dark grains had a carbon filter effect reducing the chloramine to lower detectable levels. Many very dark grains are roasted to just before a carbonizing. But the husk would easily be carbonized in the process.

  • 1
    Given prolonged contact with activated carbon reduces chloroamines, I think there could be something to your speculation. I may have to run a couple of tests.
    – Mr_road
    Mar 29 '18 at 12:34

I’d believe that a darker ales will mask more flavor compounds than lighter ones. This tends to be the case for other flavor and aroma compounds also. In my experience the same goes for double IPAs.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.