The use of wine barrels to store and age wine is a many century old tradition. Many of the world's best reds and whites are fermented or matured in these oak wonders.
The chief purpose of wine barrel aging is to fine-tune the taste of the wine by adding subtle oak flavors. Steel vats and cement vats are popular and effective but impart no flavor to the wine. Wood barrels are different. Oak is slightly porous, and well constructed barrels let in just the right amount of oxygen, which creates an ideal environment for aging wines.
The primary flavors given off by oak are toasty, spicy, buttery, butterscotch, and vanilla. You can smell and taste it. However, the amount oak flavors added, just like the fruit and alcohol must have a balance. If your wine smells like a sawmill and the fruit is over taken by the oak, then the wine has been over-oaked.
Oak is not the right choice for all winemakers. Cabernet Sauvignon and Chardonnay have an extraordinary relationship with oak. The vanilla to toast flavor suits them perfectly. However, some varietals such as a Riesling fight this relationship and the oak takes over.
Choosing the right barrel requires some knowledge and experience. There are different types of oak that winemakers choose from, depending on the desired effect. The best-known French sources of oak barrels are Limousin, Alliere, Vosges or Nevers. These are the finest money can buy. The leading sources of oak in the United States are from Kentucky, Minnesota, Missouri, Ohio, Tennessee, and Wisconsin.
There is a great deal of opinion about how the oak from different locations affect various types of wines. For instance, some winemakers believe that Limousin oak, which has a looser grain, imparts more oak flavor, while others disagree. Most agree that the American oak imparts slightly sweeter taste than the European grown oaks.
Barrels come in many sizes: 15, 20, 30, 40, 55 and 60 gallons. The smaller the barrel used, the greater the wood to wine ratio. That means that more wood will be in contact with any given amount of wine. Wines will therefore extract more flavors, needing less time. The traditional 60-gallon oak barrel is the optimum size for balancing wine through aging. A larger barrel lacks wine to wood contact, while a smaller barrel may contribute too much oak.
Contributor: Jennifer Grant (Salt Lake City, UT)