Tuesday, October 2, 2007

Lock, Stock and Barrel

The art of barrel making, known as coopering, is an ancient skill.

The oak tree is examined both before and after being cut, and wood is selected based on many criteria, including tree shape and growing conditions. These factors determine the textural variety of wood fibers, the fineness of its grain and its tannin content. Tight grain and fine tannin content are found in the best wood.

The logs must be hand split to preserve wood grain without breaking wood veins, which is essential for creating impermeable barrels. The oak log is first split in two, then into quarters to obtain wood for the oak staves. After splitting and planning, the stave wood is stored outside. Exposed to air and water, the wood is naturally aged by the weather for several years. During the aging process, the development of sugars and acids are monitored.

After aging, the staves are formed by machines into the proper shape and form for barrel assembly. After they are cut to the proper length, they are tapered at each end and beveled. Then they are planed on the outside, slightly hollowed on the inside and jointed by high precision machining.

The sharp-eyed cooper selects his staves, setting aside those that do not suit him. Then he assembles the staves inside a metal hoop that serves as the assembly jig. The cooper seals the joints by passing a wet cloth inside and outside the staves, then heating the barrel over a wood fire for approximately 30 minutes. Rendered flexible by heat and humidity, the wood fiber can now be bent by the cooper, who uses a winch to gradually arch the staves and tighten them to obtain the shape of the barrel body. The body is held trussed in place like this until the metal hoops are definitely placed.

Toasting is a signature of the cooperage. The length of heating results in a "toast level" on which the flavors of the wine aged in the barrel will partially depend. During the heating of the staves, some substances of the wood are caramelized and develop a multitude of aromas, such as vanilla, fresh bread, buttered bread, or a touch of nut, that will be found in the final taste of the wine. Toast level will be adjusted according to the customers' requests: light, medium or heavy toast. Light toast gives more barrel tannins and aromatics of oak. Medium will integrate tannins and showcase varietal characteristics Medium plus will give aromas of spices like cloves and vanillin and will be more sweet. The heavier toast will impart a smoky grilled flavor or coffee to the wine.

What's the difference between French and American oak? French oak adds more subtle flavors to wine, while American oak is more aggressively flavored. Wooden barrels allow for a small amount of evaporation of the contents during the aging period. The wine in the barrel matures and becomes stable. Co2 is released during fermentation, alcohol is formed and extraction is produced.

Oak used in winemaking is typically produced from trees of different species. These are the American White Oak, Quercus alba, harvested primarily in Missouri from 90 years old trees. The European species, Quercus sessilis, is a tree found throughout central and eastern Europe. In France it is generally harvested from the north eastern forest of Vosges, and the central forests of Allier, Never and the most beautiful of all, Troncais. These trees are usually 100 to 120 years old.

Now you have the facts of coopering, lock stock and barrel.