Storing Wine After A Party
When you serve more than one wine at a gathering, you're bound to wind up with a few bottles that are half empty. Or half full, depending on your point of view.
Unfortunately, wine is one kind of leftover you can't send your friends home with (at least legally). But you can keep it fresh for a few days while you enjoy it by the glass, wine bar style.
For the next 24 hours
If the cork is still intact, simply put it back in and store the bottle in the refrigerator. For sparkling wine, use a reclosure to seal the bottle tightly and preserve what’s left of the bubbles.
For the next 5–7 days
Pour the wine into any container that is small enough to allow only a bit of air inside. The best solution is a 375 ml wine bottle (known as a half-bottle or a "demi"). It can be closed with the same cork that your full bottle came with. Avoid using old corks, which grow brittle and porous with age.
Wine saver devices use a variety of techniques to prevent leftover wine from oxydizing in the bottle. Most of them cost less than a good bottle of wine and will quickly pay for themselves.
You can also invest in a mini vacuum pump that will remove the air from your 750 ml bottle and prevent the leftover wine from oxydizing. You can find one at any good wine store or online.