We have often talked about this subject off-camera and maybe a little on-camera too, but a way to understand off-flavors is to produce them yourself by doing all the things you were told not to do in homebrewing because you’d cause off-flavors. Mike did just that with this forced oxidation experiment with one of his beers.
Oxidized Beer Is Bad
With two glasses in front of me, I could tell right away that there was something different in the aroma of one of them. It smelled like sherry wine and it set off my brain to make a connection to the off-flavor of oxidized beer. The flavor followed suit.
There was a strong sherry taste that reminded me of barleywines that I have had. I would not say it tasted like wet cardboard as the texts say, but it was a pronounced sherry taste. Mike thought it was interesting that the hop character of the experiment beer was muted and the malt profile seemed more flabby.
We may try this beer again in a few more weeks to see how bad it can get. This experiment was eye-opening for me. Understanding off-flavors so that you can detect them in your beer is a good skill to have. Keep learning about your beer to become better homebrewers.