http://en.wikipedia.org/wiki/Champagne_%28wine %29
Aging
There is a debate about the ageing of champagne. Champagne's freshness has contributed to most people's impression that it should be enjoyed soon after purchase. Vintage champagne is often put aside to be enjoyed years after its release. As champagne ages, it deepens in colour and often develops bready, caramelized flavours and aromas.
In general the English like bottle-aged champagne with its flavours of toast and mushrooms, and the French prefer young champagne with brighter fruit and acidity. Before the era of easy transport, and when the world was subject to trade disruption (war) keeping a cellar and an inventory was important to having a constant supply. The English were crucial suppliers of capital to vintners in Champagne, Portugal, and Spain, to maintain their supply.
The English passion for the fragile and ephemeral flavours of old wine evolved from these circumstances. However young wine bought at the cellar door can be enormously enjoyable. The connoisseur's' insistence on the superiority of old wine over young is not helpful. This is very much a matter of personal taste.
The French producers are aware of both sides of the argument and produce wines for both groups of consumers. In the last fifty years, there has been a movement to produce complex wines that have aged for very long periods of time on the lees, meant for immediate consumption after release. (E.G. Bollinger RD) Such wines are probably the best compromise for the fans of older wines, as they have been cellared under ideal conditions.