While the wine shield does create a fine barrier to protect the surface of the wine from integrating with oxygen in the air, there will always be the pesky issue of all the oxygen introduced through pouring.
An alternative to the Wine Shield’s tangible barrier is one of the many neutral gas barriers that come in spray cans such as Private Preserve or Wine Saver. These systems use a gas heavier than oxygen, which is sprayed into the bottle and falls to the surface of the wine, where it sits preventing oxygen from interacting with wine. In theory, this forms an even more perfect barrier than the Wine Shield which may not seal perfectly as it touches the inside of the bottle. In reality though, we are left with the same problem of having oxygen introduced with each pour of wine.
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