Tour Stop 5: Barrel Storage

You probably know that most fine wines are aged in oak barrels. But why?  

A barrel essentially does two things to wine: it slowly introduces oxygen, and it imparts the character of the wood. That flavor will vary based on the type of oak that the winemaker uses, the level of toast on the barrel staves, and the age and size of the barrel. As wine rests in barrel, it goes through subtle chemical changes, resulting in greater complexity. Tannins that at first may be harsh and astringent after fermentation become softer in barrel.  

We have many different types of barrels here. A typical barrel is 225 liters, or 60 gallons. This is approximately 300 bottles of wine, or 25 cases. Winemakers don’t typically use just one type of barrel. They can choose from different species of oak, different toasts, different ages, and different sizes to achieve a more harmonious wine. Think of it in the same way a chef uses a spice rack to achieve more complexity in their dishes.  

The level of toast in a new barrel will heavily influence the character of the wine. A light toast may accentuate sweetness and spice; a medium toast can provide honey, toffee, and almond; a heavy toast might add chocolate, smoke, and burnt sugar.  

There are many types of oak, the most common being French and American. Rioja is well known for its use of American oak in traditional red wine-making. You can taste a number of our Spanish wines in the tasting room, which have been aged in American oak. French oak is much more common throughout the world, especially in the United States; however, winemakers use oak from Slovenia and Hungary, as well. They may use other types of wood, such as chestnut or acacia, although that is much less common. Each of these different types of oak is used for the different flavors they contribute to the wine. American oak typically imparts notes of dill, coconut, and vanilla, whereas French oak more often imparts notes of baking spices, such as clove, cinnamon, nutmeg, coffee, and mocha. Our winemaker currently uses a variety of cooperages, including Radoux and Sansaud from France, along with Murua, a Spanish cooper with which Valdemar Family has had a longstanding relationship. In our cellar, we have French and Spanish oak right now. 

There are other differences between French and American oak as well. The grain of the oak varies depending on the species, with American oak having a less dense grain and French oak having a much tighter grain. The density of the grain either slows or accelerates the ingress of oxygen into the wine. Winemakers take all of these factors into account when determining the barrels they will use for each wine. At any given time, our winemaker will have 5-8 wines aging in barrel. Some will be bottled by themselves, whereas others are intended to be part of a blend. As we talked about earlier, some of these barrels hold the press fractions from the wines we pressed off after fermentation. They will be blended in small percentages into the final wine. 

In addition to choosing the type of oak, our winemakers can choose the age of the barrel. As the barrel ages and gets older from use, the amount of flavor imparted by the oak diminishes. A barrel generally gets about 50% of its flavor and character extracted in the first use, 25% in the second use, and less after that. Winemakers use older barrels when they are looking for the softening that comes with the introduction of oxygen without the overt oaky tones that come from new wood. If our winemaker has a full-bodied Cabernet, she may choose new oak for aging, as the flavors and aromas imparted are a good match for structured Cabernet. 

Winemakers may also vary the size of the barrel. Smaller barrels will impart more oak flavor to the wine, whereas larger barrels will impart less oak flavor, because the wine has less surface contact with the barrel. Using barrels well is truly a fine discipline of skilled winemakers. 

Barrels are expensive! A single American oak barrel averages $500, and French barrels cost anywhere from $1,000-$1,800 each. The initial investment for a winery barrel program is extensive. Likewise, the additional costs involved in aging the wine are high. Wine can sit in barrel anywhere from 6-30 months, during which time the winery accrues considerable expense to maintain the wine. A winery will not recover costs until the wine is sold many months later.  

Humidity control is crucial to storing barrels and aging wine. Humidity is important because wood is not a natural barrier to water vapor, alcohol, or oxygen. As wine ages, water and alcohol diffuse out through the wood, while oxygen diffuses in. It is important for the wine making process that the vapor diffusion outward is slowed down, but not stopped, and this is done by storing the barrels at a high relative humidity. 

Our cellars have advanced humidity control systems. These machines monitor the humidity and temperature in each room and make small adjustments to ensure consistency. All of these systems are linked into a larger temperature and humidity control system for the entire winery, which we monitor via computer.