How long will a bottle of wine last after it is opened?
It largely depends on quality and type of wine. Better-made wine will last longer after opening. Techniques such as gas-injection or vacuum sealing buys a little more time, but not much in most cases.
Air is the reason wine declines, and air happens the minute you open the bottle. It doesn’t really matter how much air—if any—is in the bottle after re-closure.
Rule of thumb: put re-sealed bottles in the refrigerator to stretch life.
Quality white wine can last up to four days in half-filled bottle. A superior white with high fill could last a week or more. Mass-produced, commodity white wines do well to stagger along for a day or two.
Quality red wine will last three or four days in the fridge. More robust and tannic the wine, longer it will last. A red with puckering tannins can last up to a week and may even benefit from the air exposure for some of those days. As with whites, lower-end reds die in a couple of days.
Their own carbon dioxide bubbles protect sparkling wines, but there must be a perfect seal on the closure. Quality sparkling with a high fill might last four days or more, but finish the bottle the next time you open it. A bottle with a half-fill or less likely is done as a sparkler in two days.
The good news is a quality sparkler without fizz remains good wine. Enjoy it as quality still wine for up to a week. Cheap sparkling might not last until dawn.
Sherry made in light-color fino and manzanilla styles may last a week, but they always are best when opened. Sherry in darker amontillado and oloroso styles can live two months or more.
Life after opening for port also depends on style. Ruby Port and LBV easily can handle a week; 10-to-40 year old Tawny Ports last three weeks—if specially sealed, stretch that to three months.
Madeira, oxidized in making, is king of longevity. Keep bottle away from light, it can last a year, often much longer.
Last round: Where there is wine, there always is a way.