The moment you uncork that bottle to have a sip, wine is exposed to air, as well as the moment it is subjected to air, the oxidation takes place, which ages it too rapidly. Exactly how do you know if your wine has been oxidized? It will look brownish, and also will certainly not taste as fruity as it need to (or has in the past). Oxidization can be a result of a damaged cork, or a custom wine stoppers best being kept too long after having been opened up. Wine can additionally sour when subjected to excessive light, called lightstrike.