How long does wine last after it is opened? Well it depends!
I have used this simple and affordable and very effective method for saving wine from an opened bottle for a long time. A great advantage to this is you can open a few bottles or more with friends and try a few things. No need to finish a bottle or have any complicated method to save the wine for the next day or week or month in this case. Platy make the water bags that hikers and outdoors people use. They know their stuff.
These Platy Preserve bags are food grade plastic so no weird taste transfers. Just pour the wine in the bag. (a funnel makes it easier) Then squeeze out the air and put on the cap. It can go in the fridge and the way the bag is made it will stand upright. There is an erasable area on the back that is for writing the wine information.
I have used these bags for keeping wine fresh for weeks at a time. At 800 ml they hold just a little over a full bottle of wine. They are also great for camping or boating or anytime you want to bring along some wine without a glass bottle.
if you just recork the bottle here's some info from Bon Appetit
The best way to keep wine after you’ve opened it, is to remember to recork it and put it in the fridge. By recorking and refrigerating, you’re limiting the wine’s exposure to oxygen, heat, and light. These are all the things that take a bottle of wine from being next-day-decent to downright disgusting. If you were responsible enough to remember these precautions before you hit the hay, a bottle of red or white wine can last approximately between two and five days. For sparkling wine, you have one to three days (it will for sure go flat, but it’s still drinkable, and sometimes chugging flat sparkling wine after a long day is better than no wine at all). A wine could go bad in a day if it’s an unstable natural wine, or it could last for a week if it’s a highly tannic, commercial red you haven’t touched since the night you accidentally opened it.