The year - or vintage - refers to the year in which the grapes were harvested and the wine made. It does not refer to the year in which it was launched onto the market, as the wine may well have been stored in a barrel for a period of time. Although the year does not have to be stated, it is generally printed on the label.
The year gives a good idea of the quality of the wine as the weather conditions that marked the year in question will have had a huge impact on the characteristics of the wine. A hot year with sufficient rain but a dry harvesting period is likely to be a good year. However, these are not the only criteria to be taken into consideration, as there can be substantial variations in quality from one estate to the next in one and the same year. Such variations reflect, among other things, winegrowing expertise and techniques.
Stating the year is also useful for aging purposes. Long-term storage is, in general, more suitable for wines made in years considered good or excellent. Wines produced in years when the weather was less favourable should be consumed without too much delay.