Unlike other types of wine, champagne and other sparkling wines do not improve as they age. Buying champagne shortly before an event is better than storing it for years or decades, because champagne loses its effervescence as it ages and becomes flat and stale. However, unopened champagne keeps for a short time if it is stored properly. If you find yourself with extra bottles of champagne and you can't find a reason to celebrate, careful storage will keep the champagne fresh and bubbly as long as possible.
Locate a cool, dry, dark location, such as a pantry.
Place unopened bottles of champagne on their side in the location you chose.
Chill champagne before serving by putting it in the refrigerator for two to three hours or placing it in a bucket of ice water.