Fermenters Forum

I've never made wine, but I think I know exactly what you mean by the rubber stopper smell- and just recently had been having this problem with some of my beers. I've gotten advice from possible oxidation, to infection, to using a rubber stopper without soaking it in something first.

And after trying a couple of test batches and constant searching on the forms, it seems the answer for me is fermentation temperature: too high.
The rubber stopper (or what I called burnt plastic as well) smell seems to be an off-aroma/ flavor from sulfur compounds given off by the heat stressed yeast. Low and behold, after I fermented at 18-19C instead of 20-23C. The problem was solved.

Possibly this could point you into the right direction to fix your wine as well? The good news (so I've read- I dumped my rubbery pale ale) is that the yeast will clear it up if given long enough

I've gotten that off flavour in wine & mead before, tastes just like a rubber stopper smells; I'm convinced it's due to high fermentation temps. Those are fusel alchohols causing it, but the good news is that they'll age out; might take a while, but they do indeed age out.

The only way I've found to avoid this is to control the temp during fermentation. Try to keep the temp closer to the low end of the suggested temp range on the yeast packet/vial. Keep in mind that the actual temp of the fermentation will be a few degrees higher than the stick-on thermometer strips on the outside of the carbouy indicates. The yeast actually generate heat during fermentation.
Hope this helps. Regards, GF.