What varies between wines, and vintages, is the amount of time that the maturing process takes, and the degree to which it takes place.
Great red wines, fortified wines and sweet white wines can age and gain in character for decades. This is because — in very simple terms — they have plenty of fat to live on. For a wine to age for a long time, and become complex and interesting in the process, it must have very great qualities at the beginning. Rare is the wine that starts simple and ages to complexity, though some great wines can taste simple in youth owing to tannin or acidity masking their underlying flavours.
Some wines are made to age, some to drink while young. This is partly a decision oŁ the winemaker, partly a matter of terroir, grape variety and weather. Each of these factors bears upon an individual wine.
To explore one example: the 1980 red bordeaux could never last as long as the 1982s because 1980 was a cool, damp year, while 1982 was a warm, dry one. In particular, the weather was good at the right times in 1982, and poor at the wrong times in 1980; the overall weather statistics for the two years, in terms of rainfall, were (on paper) very similar. The 1982 grapes were very ripe, the skins were well coloured, the rain in October was late and did not dilute the juice. With super-ripe grapes, wine-makers felt able to expose the wine to plenty of new oak in its initial cask-ageing. This adds tannins and other complexity-inducing components to the young wine. All in all, the 1982 wines are predicted to have a life of decades, while the 1980s were mostly past their best by 1990.
Wines made under the same climatic conditions may differ in their ability to age owing to underlying terroir, linked to the mixture of grape varieties used. Different grape varieties grown in adjacent vineyards will make wines with very different ageing potential: Camay and Pinot Noir grown in Beaujolais and Burgundy are examples. Camay wine is low in acidity and tannin, high in fruit. It develops fast, but has a short potential life span. Pinot Noir has more tannin and complexity, and thus has the ability to age for tar longer.
A winemaker may decide to make two wines from the same estate: one which is destined to age, the other for early drinking. His decisions as to the length of time the new wine spends in the fermentation vat, how the wine is aged, and when it is bottled, will contribute to the varying characters of the two wines.