there are very few wines that are better to be saved. Most wines are made to be drunk now and would just lose their fruit and power to be saved. Or to put it another way: They are not getting better with age - quite the contrary.
There are many factors which determine whether a wine can be saved not to be enjoyed now. It is factors such as tannins, acid, structure and anti oxidanterne in the wines. But the process also this wine has been through, when it was made, has implications for how a wine will evolve with time. Among other things, a large part of the wines that can be stored stored in casks for a longer time.
If we start with the light wines so need a white wine that has been aged in casks, such as many sauvignon blanc wines, often preferably be drunk within 12-24 months. A chardonnay that has been fadlagring can, however, save a bit more. Some wines bl.a. riesling from Germany, chardonnay from Burgundy can be saved any longer, which is especially due to the high acid and for the latter a fadlagring. But it means far from that, all of the wines from these areas can be saved for a longer time. And conversely, there is also chardonnay and riesling wines from other countries as well can be saved. Here, one should check what the house says about the wines or ask your wine merchant.
In the redwine is, as previously mentioned, a combination of antioxidants, tannins, acid and the process the wine is made during the making of a wine can be stored for a longer time. The vast majority of the wines sold should be drunk within 2-3 years and are not getting better with time. However, there are exceptions. Nebbiolovinene from the Piedmont region are often very durable and the ones you can often save a part no longer. A Barolo can f.ex. in any case, be stored up to 50 years. Also a few wines from Bordeaux and Burgundy can be stored for a longer time.
The sweet wines, however, can often keep for a long time. The most well-known is Vintage Port and Sauterne which gets the extra complexity of storing.
it Is a wine first, open is the durability is very short. Put a prop on and put the cool f.ex. in a refrigerator, you can prolong the shelf life. It is my experience that a white wine often must be drunk within 48 hours while a red wine should be drunk within 72 hours. But the older it is and the more tenuous the faster lose the taste.
A sparkling wine is, however, often flat after 24 hours. However, you can easily save a sweet wine for a longer time. And in particular, the oxidized wines such as a port or sherry. A tawny port, you can easily have standing for a month while a ruby port is losing a part of the taste after a week.
With the bag-in-box wines, this is something different, as they have a system, so that can't get air into the bag. It means that a white wine can often be stored up to 2 months after you have taken the first glass. A red wine holder a month more in my experience. The wines are not outright bad but it loses a little in taste.
white Wines: chardonnay wines from Burgundy, riesling from Germany and Australia, semillon from Australia, and the trebbiano of Lugana (Italy).
Red wines: Some good wines on the cabernet sauvignon or blends from Bordeaux and California, pinot noir from Burgundy, Barolo, Barbaresco, Rioja Gran Reserva, each of the sangiovese wines from Tuscany, fol.a. Brunello d Montalcino wines.
Sweet wines: Sauterne, sweet Riesling from Germany, Vintage Port.