I have been using these at the insistence of my spouse, as we often have a half-bottle remaining. But I don’t see the point. What it does is reduce the atmospheric pressure inside the bottle by some unknown amount, perhaps to 1/2 to 1/4 atm. Presumably, this reduces the amount of available gas to react with the surface of the wine. But the mass of gas inside the bottle (about 300mg) even when un-sucked by this thing is far less than the mass of wine about 500g), and of that, air is about 20% oxygen so we’ve got only 60mg of oxygen to worry about. I agree with the “double-blind test needed” comment above.
