Since I keep around 100 bottles open, evaporation is a concern of mine. I picked up several tapered silicone wine stoppers while in Palisade this year thinking they might be the perfect cork stopper replacement. I decided to do an experiment. I put a stopper in a shot glass and filled it and an empty shot glass with FRYL, covered them, and left them for 2 months. Tonight I did a blind tasting and could clearly pick out the silicone batch. Also the stopper had bleached out a bit. FWIW I'm not using the stoppers.