A big question for wine lovers all over the world, is whether a bottle is ready to drink, or ‘prête à boire’. Since wine changes with age, some excellent wines may be barely palatable if drunk too young. On the other hand, wait too long and you may find your wine lackluster, a pale shadow of what it could have been had you drunk it when it was at its peak.
It really depends on four main factors:
The grape variety used to make the wine. Some varieties will, as a rule, cellar longer than others. Sauvignon blancs are generally designed to be enjoyed young, for example, while a a top qualityPinot Noir may need many years to reach maturity.
The quality of the fruit. To make a top quality wine with the ability to develop in the bottle, requires top quality fruit, and top quality winemaking. That bargain bin wine from the supermarket is undoubtedly intended to be drunk now!
What the winemaker intended when they made the wine. Some wines are deliberately made to be drunk young, and some are designed to improve with a certain amount of bottle aging.
Your own personal tastes. Some people prefer to drink wines at an earlier stage in their development, while others enjoy the more mature flavors of a well-aged wine. As a rule, younger wines will tend to be fresher and crisper, with more obvious fruit character. Aged wines will be softer, more complex and have more 'bottle developed' secondary characters. A young pinot noir, for example will exhibit more cherry and strawberry fruit characters, while an older one will have more 'forest floor' flavors - mushrooms and savory characters.
Remember that wines need to be cellared with respect. Out of the sunlight and at a constant, cool temperature are the keys to letting your wine mature gracefully.