How the barrel is made

Two factors determine the final result: the way the staves are obtained (split or sawn) and the barrel toasting during the barrel forming process.

Obtaining the staves

This operation is performed prior to drying and depends on the type of oak used. Once the trees have been felled, the trunks are cut into logs of 0.9 - 1.2 metres in length. These in turn are quartered and this is when the differences start to appear.

• If the staves were obtained by sawing, then 6 staves will be obtained from each quarter, of varying widths. This procedure is valid for the dense fine-grain American oak. The yield is high: 2 m3 of wood give 1 m3 of staves (1 m3 of staves serves to construct some 10 Bordeaux barrels).
• If the staves were obtained by splitting, then the yield is lower, with just 3 staves per quarter (5 m3 of wood give 1 m3 of staves). This system is applied to the French oak, as its high porosity and thick grain do not permit sawing (which would cause barrel leaks if the fibres were broken with a saw).

Barrel toasting

A Bordeaux barrel is formed by 33 - 36 staves, with a thickness of 27 - 28 mm. These staves are not joined by nails and rivets, neither are there any seals between the staves; the barrel is maintained watertight simply by the great pressure obtained during the heat bending process.

The process is as follows: first the barrel is pre-formed by securing the staves inside a metal hoop or ring. This type of wigwam is then put over a brazier with a fire made from the left over wood cuttings. The inner stave face is then heated to make it more flexible. A rope tightened by a winding drum and crossed over inside the barrel, starts to gradually bend the staves inwards, whilst they are constantly dampened to prevent splitting. In this way the barrel gradually takes on its traditional pot-bellied shape.

However the heat, in addition to making it possible to bend the wood, also modifies the organoleptic qualities of the barrel which, during the ageing process, will impart the so-called empyreumatic aromas to the wine, such as vanilla, toasted almonds, coconut, smoke ...

The degree of toasting (low, medium or high) logically conditions the concentration of these compounds.