very interesting articlehttp://www.better-bottle.com/pdf/Closur ... _Study.pdf
That is quite an interesting article (OK, I just looked at the pictures) But I still get what is going on. I wonder how much this could actually affect the taste as I would think the production of the heavier co2 would continually push out the oxygen that may be entering through the stopper/airlock. As far as after fermentation, well I guess its good that I age in kegs. It would be interesting to see the same experiment done with a simulation of co2 production in the vessel.