My recent experiments with homemade sauergut are definitely beginning to prove this to be the case. If we’re all talking about the same “flavor”, I almost always taste it in imported beer from Germany, but rarely in similar American lagers. If it was grain related, I’d think it would be more common in American beers. I have a Pilsner fermenting right now that should help me make a final decision. I’ve used it in a Hefeweizen and a Vienna lager so far and I like the results.DM's post said Veltins did not have the flavor... The flavor is like grape juice or even a bit of grape jelly. Sounds odd paired with beer but that is the flavor. I do not think it is grain related or it would show up more often in all beer styles. Seems pretty straight forward that the flavor comes from the use of sauergut in German brewing. They are pretty much the only folks who use sauergut and are the only ones to produce commercial beer examples with the grape flavor in my experience.
I have never picked up the flavor in the cereal Grape Nuts.