I've noticed what I describe as a "plastic bag burp" property in some beers. In short, beer burps after drinking the beer have a slight plastic-y aftertaste.
I notice this most often in home brew and in some less-than-stellar craft beers, but I also notice it in some (but not all) of the classic bavarian hefes (e.g. Weihenstephan, Paulaner). Given that weissbier connection I'm wondering if it's a sign of a specific ester or phenolic byproduct, specifically sought for in the bavarian beers, and accidentally produced in the home brews.
I'd love to know what specifically that taste might be coming from, and for bonus points how to avoid it when it's not true to the beer style's taste profile.