Wine that hasn’t been aged is no more than fruit juice. Wine that has been aged too long tastes vinegary and too tart. Like Goldilocks, you want your wine to be just right. Still, some wines age better than others. Here’s why.
Aging wine is dependent on a chemical process called oxidation – the interaction between oxygen and the acids, alcohol and polyphenols (things like tannins, color pigments and other flavor compounds) in the original juice. Phenols are particularly important, as a higher concentration of phenols and a deep color usually means the wines will spend more time in the aging process, leading to deep flavors with subtle differences due to the original strain or blend of grapes.
Terroir – the environment in which the grape is grown – includes factors such as climate, elevation and ground qualities. The same grape variety grown in a different terrior will produce a completely different wine. Terrior also has a strong effect on tannins, and the ripeness of a tannin is a major factor in how well a wine ages. Terrior and the richness of the soil also affect yield, as the grapes and their vines actually compete for nutrients. Higher yields typically mean fewer phenols. Finally, older grape vines tend to produce better-quality grapes.
Beyond the variety, environment and growing process, the wine-making process also makes a difference. For example, the length of time the grapes are left to macerate after they are crushed affects the amount of phenols extracted, as does the temperature at which the grapes are macerated. Adding sulfur dioxide limits oxidation but is necessary to the process; the amount and timing are critical. Filtration, yeasts and whether to age in oak barrels (including how new the barrels are) all affect wine aging.
There’s always anticipation when you open a wine bottle. Even when everything seems to be right, a wine may not age well. In other cases, a wine low in tannins and pale in color (which usually means it will age poorly) turns out to be surprisingly good 30 years later. The longest-lived white wines are found among Sauternes, German Beerenauslesen and Tokaji. Burgundies and Bordeaux are the classic red wines, while the wine known as Condrieu is not very suitable for aging in the bottle. Wine-making is an art because there are so many different factors that affect aging.