Champagne will keep for a longer period of time if it is not opened. If you want to save a good bottle of champagne for a particular occasion, let it alone and store it properly. Sealed champagne has a shelf life of three to four years if it is non-vintage and five to ten years if it is vintage. To ensure that your unopened champagne lasts as long as possible, it's important to store it properly. Vintage and non-vintage champagnes can indeed be consumed three to five days after the bottle has been opened if kept properly. If you ever open a bottle but don't finish it when throwing a party, this information might be helpful.