The Influence of Barrel Storage
Generally speaking, fermentation is not an easy process for the grapes. Many wines emerge from fermentation with rugged textures and colors. This is why the practice of aging was put into place: to simply give the wine time to settle out of its unrefined form.
To get the most out of the aging process, early winemakers discovered that storing freshly fermented wine in oak barrels directly influences the flavors of the wine. Wooden barrels provide oxidation. You may have heard that wines are better when they are allowed to "breathe." What people mean by this is that some exposure to oxygen can add complexity and richness to both the flavor and texture of the wine. Oak barrels provide this oxidation in a gradual and controlled way that maximizes the benefits of air without overdoing it.
Wooden barrels also infuse aromas into the wine. Though found in nature, oak wood is actually quite complex chemically. Natural compounds that appear in oak include vanillin, which produces a vanilla smell; terpenes, which elicits the scent of black tea and tobacco; and furfural, which emits toasty almond scents. Combine these with the general woodsy flavors of the oak, and it is easy to see how the wine would emerge smelling and tasting differently after aging.
Although wine barrels are almost exclusively oak, different types of oak embody varying levels of these chemicals, thus contributing different flavors. The winemaker uses the barrels just as a chef uses a spice rack, considering the chemical complexity of each barrel and the proper degree of exposure to bring out the best in the wine. As other industries have evolved their packaging techniques and started using metal, stainless steel and eventually plastic containers for shipping and storing their goods, winemakers have stood by the influence of the tried and true wooden barrels. The process results in fine wines with flavors and aromas as complex as the unique barrels in which they are stored.
