It is a common misconception that the aging of a wine equates to the improvement of a wine. Aging a wine simply means changing it, not necessarily changing it for the better. It is important to keep in mind that most bottles of wine produced today are intended for immediate consumption. It is estimated that up to 90% of wines are best consumed within one year after bottling has occurred, and that up to 99% are best consumed within five years after bottling has occurred. Of the 10% of wines that have the potential to improve with aging, experts generally agree that 5-10% will improve after one year, and that only 1% will improve after 5 or more years. With this is mind, the types of wine you choose to age, how long you choose to age them for, and how you age them are all extremely important factors if you plan on improving a wine through the aging process.
The best place to start when choosing what types of wine to age is in understanding the role that tannins play in wine. Tannins are present in the skin, stems, and seeds of grapes. When a grape is young and not yet ripe the tannins make the grape taste bitter and sour. This is a defense mechanism of the grape to prevent birds and other animals from eating the grapes before the seeds have fully developed and are not yet ready to be spread. Not only do the tannins make the grapes taste bitter, they combine and chemically react with saliva to make your mouth dry and to pucker. The dry, sandpapery feeling in your mouth caused by tannins is called astringency. Tannins are responsible for the two most important characteristics of wine, astringency (or mouthfeel) and bitterness.
It’s commonly held that tannins are the single most important factor in aging a wine. While tannins themselves do not have a scent, their reactions with wine alcohols and wine esters will change and control the aroma. A wine that was flowery and fruity while it was young will become more subdued and complex in aroma as the chemical reactions take place. It will develop from younger and fruitier smelling, to more mature and wine-smelling, to complex, leathery, earthy and nutty. As polymerization happens, chemical chains of tannins become longer over time, causing them to fall away and the wine to become smoother and sweeter. Tannins are also highly reactive with oxygen. When oxygen mixes with the tannins a chemical reaction takes place that will alter the molecules in the wine. However, if too much oxygen enters at one time this process will occur too rapidly and ruin a wine, causing the tannins to be overwhelmed and the other molecules to become oxidized.
This is where the method of wine storage becomes elemental in the aging process. Because heat causes the rapid oxidation of wine that will ruin it, it is important to keep your bottles stored in a cool environment of about 55 degrees F, away from sun exposure, and in a stable and humid climate that will not allow porous corks to let in too much air at once. The best way to achieve these storage conditions is to invest in a wine cooler refrigerator, wine cellar, or a custom wine room. While each of these storage options have their own unique benefits they are similar in their ability to create an environment that is suitable for any wine that you are attempting to age.
Understanding the role of tannins in wine and how some of the chemical processes that occur during the aging process is also helpful when it comes to selecting a wine to age. Wines that are rich in tannins and are high in acidity are best for aging. Red wines are much richer in tannins than white wines, and wines aged in oak barrels will have higher tannin content than those that are not. While red wines are typically chosen for aging, white wines like Riesling and oaked Chardonnay are still eligible for aging because they are high in acidity and have a higher tannic content than other white wines.
Wines with good aging potential: Cabernet Sauvignon, Merlot, Pinot Noir, Vintage Ports, Syrah, Bordeaux, Riesling, Chardonnay
Wines with poor aging potential: Rose, White Zinfandel, Sherry, Sparkling wines, branded wines like Yellow Tail and Mouton Cadet, Inexpensive wines