According to Still Tasty, an unopened bottle of sparkling wine usually does not go bad but is best consumed within three years of production. Sparkling wine goes flat quickly after it is opened and is best consumed the same day.
Proper storage of sparkling wine ensures that its quality is maintained. Sparkling wine should be stored in a dark area, away from direct heat and sunlight. If the wine is being stored for more than a few weeks, it is best to lay the bottle on its side, allowing the cork to stay moist and airtight. The wine should not be consumed if it develops an unusual odor, taste or appearance.