History of the barrel II: the origin of oaks and the barrel construction

There are two countries in the world that, due to the climate and the soil’s characteristics, allow an optimal growth of oak trees: the United States and France. However there are other world regions where a good quality oak is recently being produced. Such are the Iberian Peninsula and Eastern Europe.

In France, two main oak groves can be found. One is located in the central region, in the area of Nevers, Allier and Tronçais. The oak trees grown in this region belong to a species known as Quercus petraea or sessilis. This kind of oak tree needs poor and sandy soils, in which they grow thin and tall, with a very short distance between the tree rings due to the slow growth, thanks to which tight grained wood is obtained.
This kind of wood’s tannin content amounts to 45 gram/kg and is one of the most suitable for wine ageing. This kind of wood is marked by its spicy aromatic notes.

In Limousin, lands are fertile and the species Quercus robur or pedunculata is abundant. These are thick, dwarf oaks with a high diameter trunk. Its wood is porous and wide grained as the separation between its growth lines is wider. It has high tannin contents, 55 gram/kg, and imparts aromas of toasted almonds and caramel. It is used in the ageing of wine spirits such as Cognac and Armagnac.

Quercus Alba is the most representative of the American oak species. It is grown in the Eastern Coast of the US. It is a strong texture oak and its wood provides the red wine with less tannins, it is richer in vanillin and lactones, which impart vanilla and coconut aromas to the wine. As a result of these features, softer and lower astringency wines are obtained with the use of American oak barrels. They are used not only in wine ageing, but also and mainly for the sale of whisky industry.

Many factors influence the elaboration of the barrel: the way the staves are cut, dried and assembled and the degree of toast applied to the barrel.


There are two ways to cut the staves (the wooden pieces from which the barrels are produced): sawing and splitting. Due to its low permeability and its strong texture, the American oak can be sawn. With this system, a higher output is achieved since when splitting the staves, system used with French oak, between 40% and 60% of the wood is lost.

When drying the staves, the wood moisture content is reduced, obtaining 15% moisture at the end of the process. This is how a green and aggressive wood is transformed into a dry and aromatic wood, which has lost some of its bitterness and astringency. The ideal way of drying the staves is the natural air-drying system, in which the staves are left outside for two or three years allowing weathering. During this time the weather and the microorganisms act on them. On the other hand, the use of drying kilns optimizes the drying time. It is a cheaper process, but the barrels obtained have a lower quality.

The assembling of barrels is a craftwork. No nails or glue are used in the assembling of the staves. They are bent into shape thanks to the precise application of heat and water and, with the help of galvanized rings, until they take the form of the barrel.

Finally, the toast consist of burning the inside part of the barrel on oak or electric fire. There are three degrees of toast: soft, medium and strong. They impart different ageing aromas.

There are also other differences to be considered between the French and the American oak. For example, French oak trees used to produce wine barrels take nearly twice the growing time of the American oak trees. There is also a big difference in the amount of staves produced out of a tree: from 1 m3 of American oak four barrels are obtained, while only two are produced out of 1 m3 of French oak.

From this information, we can infer the price difference between the 225 l standard French oak barrel, which amounts to 500-800 euro, and the American oak barrel, which amounts to 250-400 euro.

Esta entrada fue publicada en Winemaking and tagged , , , , , , , , . Bookmark the permalink.

Leave a Reply