If there is one thing people feel they know about wine, it is that some bottles, especially very old bottles, are quite valuable. Wine is a simple product of the fermentation of mashed grapes. Its quality may vary greatly due to climate, soil, age of the vines, genetics of the vines, and most importantly, the skill of the winemaker. Every year the climate changes, bringing variations to the final product that are classified as vintages.
Winemakers come and go, often leaving their mark on each successive vintage.
As in any profession, some winemakers exhibit greater skills than others. All of these factors are combined to produce the final test of the wine, its quality. Each of the wine producing countries of Europe have tried to qualify this ethereal concept of quality by defining procedures and yields to be followed for specific regions. Certain vineyards and regions have been recognized as being an historic factor in the quality of the wines, and as such are rewarded in some way. This classification system allows for instant recognition of quality, just by glancing at the label.