If you’ve ever bought a bottle of red wine and, unable to finish it, covered the mouth of the bottle and then tried to drink a glass a few days later, you know what an unpleasant experience this can be. As soon as oxygen hits that complex beverage, it begins to degrade and pretty soon it ends up tasting more like vinegar than wine. The Coravin is a novel way to let you have one or two glasses without having to finish the entire bottle at once.