Inspired by a recent discussion about foaming and head retention I conducted a simple experiment where I shook up one beer sample repeatedly while the other was shaken only once. That one time shaking was necessary to make the experiment simpler.
In the end I was not able to detect any significant difference in head retention between both samples. I don’t think that it is a myth that foaming affects head retention, I just think that its impact is too small to be noticed by this experiment.
I agree with you, Kai, that I don’t think it’s a myth, but I’ve never been able to detect any negative effects. I’ve always wondered if maybe it’s because I have enough foam positive elements in the beer so that even if some gets “used up”, there’s still plenty.