History of Use
In the early history of wine making, ceramic vessels were solely used for the storage and transportation of wine. Because wood can fall subject to nature and time, tracing the history of using barrels in wine making has proven to be difficult. In ancient Mesopotamia barrels made from palm wood were used to transport wine along the Euphrates River. Specific properties of palm wood caused it to be a difficult material to bend and fashion into barrels. As a result wine merchants from different regions began experimenting with different wood styles.
Historians have been able to detect that oak has been present in wine making for at least 2 millennia. Ancient records show that oak first came into use, on a widespread basis, during the Roman Empire. Over time, wine makers found, that along with being great for storage and transportation, the oak barrels also imparted beneficial properties that helped to improve the wine. In some cases the barrels made the wine lighter and better tasting. In the United States, during the 1960s and 1970s, Robert Mondavi helped to expand others’ knowledge about the different types of oak and barrel styles.
Source of Oak
Just like the name implies, French Oak Barrels are from France. There, two different types of oak trees are used to make barrels; Quercus robur (common oak) and Quercus petraea (white oak). In order to find those oaks, one must travel to either the Allier, Limousin, Nevers, Tronçais and Vosges forests. Just like grapes, the different types of soils found in each of these forests produces wood that carry slightly different characteristics. It is commonplace for many winemakers to use barrels from different cooperages in different regions. This practice not only brings the different characteristics of the wood to shine, but the different degrees of toasting also help to enhance the final product as well.
Properties of Oak
Oak trees used to make the barrels are typically harvested when the tree is between 80–120 years old. The ideal conditions for growing are a cool climate in a dense forest region that allows the trees the chance to slowly mature and develop a tighter grain. The ideal conditions for harvesting are in the winter when the tree contains less sap in its trunk. It’s typical for one tree to provide enough wood for two 59-US-gallon (220 L) barrels. However, because the wood is split along the grain only 20-25% of the tree can be used to make barrels thus cutting into yield per tree.
As stated above, French oak typically has a tighter grain which also leads to a less watertight nature. As a result the wood must be aged/seasoned for about 24-36 months in the open air. This open air seasoning causes undesirable naturally-found chemical properties and bitter tannins to be leached from the wood. Sun, rain, and wind all help with the seasoning process. In drier climates water is added to aid in the seasoning process. The result of seasoning is a “mellower” oak that can only be procured using this method, as kiln-drying can not duplicate the effect.
Effects on Wine & Advantages of Use
Wine aged in French Oak Barrels generally has silky and transparent tannins, which help the sugars and fruity flavors of the wine to persist on the tongue. Depending upon the variety of grape one might also note hints of spices, and toasted almonds along with the notes of different fruits and floral aromas that are present.
While there are two different types of oak used to make barrels, Quercus petraea (white oak) is considered to be far superior in quality. The higher quality is found in its finer grain and richer contribution of aromatic components like vanillin and tannins.