For this entry, I figured it would be easier to just make a video.
Cork taint is caused by accumulation of a molecule called 2,4,6-trichloroanisole (TCA) in wines. It makes the wine smell like an old basement. Musty, cardboard, soil, moldy. It’s generally believed that chlorine used in winery/cork sanitation can combine with phenolic groups to form chlorophenols. Chlorophenols are very toxic to things like microbes which might be growing on a cork (or a palette or a barrel). The microbes, which would prefer to stay alive, will detoxify the chemical by O-methylation of the phenol, producing TCA and other analagous compounds.
I should point out that I didn’t really observe any plastic-like flavors or aromas in the wine. With shorter contact, you can probably minimize any off-aromas while still extracting the TCA.
Refs: Simpson and Sefton, “Origin and fate of 2,4,6-trichloroanisole in
cork bark and wine corks”, Aus. J. Grape and Wine Research, 2007
NYT article mentioning plastic wrap as treatment for cork taint