I don't really know, but I just found two bottles of "Cold Bear" and "Black Bear" blackberry wind that I know were from the early 70's. That makes them nearly 40 years old. And they still look good.
No, it is a fortified wine.
A fortified wine is a wine that has had a spirit added to it in its fermentation stage. This adds a different flavor to the wine as well as preserving it. the sweetness of the wine is usually determined by when the alcohol is added in the fermentation stage, the sooner, the sweeter.
port
fortified
what are the characteristic of fortified wines
The introduction of the port wine which is a sweet fortified wine from the Douro region of Portugal.
port
Madeira
Port is a good example, the wine is fortified with the addition of a Brandy (distilled grape spirits), in order to stop the fermentation and to boost the alcohol content. The wine is then stored and aged before being bottled.
Fortified wine does not contain any carbon dioxide. It is made by adding alcohol or brandy to a table wine to increase its alcohol content. If it had carbon dioxide it would come under the head sparkling wine.
Table wine usually has anywhere between 7 and 15% alcohol by volume, and fortified wine has between 15 and 22% alcohol by volume.
An aromatic wine is a fortified wine (have added brandy or wine alcohol, and is usually sweeter than regular wine), but is distinct from a fortified wine in that it is also flavored with herbs, roots, flowers and/or barks. it is considered an aperitif (served before dinner as a digestive stimulant).