Nice, short and to the point explanation! I just kegged my 16th batch of beer with a new method on fermentation, and i realized that it smelled horrible. The taste was better but quite muted and with a distinct off-flavor. The beer was a Sierra Nevada Pale Ale Clone from BYO Magazine and my new variable was fermenting it in my living room at room temp (20-22c) because I am using Voss Kveik yeast that allows higher fermentation range. But what i did not think about is that my living room has a lot of light and I'm fermenting in a clear glass carboy... Could be I did something else wrong but it seems to match up with this information. So I probably fucked up my batch due to light exposure. Thanks!