I don’t remember what the concentrations were, but it was done as a group and it was really interesting to see how differently each person in the group scored on the flavors/aromas. The most interesting to me was my ability to suss out the “skunky” mercaptans caused by exposure to light. I could perceive them at way lower levels that the others.
This made sense to me, though. One of my favorite beers, DAB, comes in green bottles, which do little to protect the beer from light. It’s protected by being fully enclosed in a cardboard box. However, I was amazed one afternoon that I could detect “skunkiness” in a bottle that had only been exposed to occasional light when opening the refrigerator door after the box was opened.
