At Château Haut-Brion, most of the wine is put in new barrels for a period of 18 to 24 months. This use of new barrels goes back to the beginning of the 18th Century -- when it was learned that old, poorly cared-for casks would spoil the new wine. This marvelous vessel allows a single man to easily handle and move the contents of more than 300 bottles.

Furthermore, a new cask happens to be the ideal recipient for maturing great wines. The oak diffuses tannin, throws off impurities and develops fragrance. The wine, charged with CO₂ during fermentation, releases the gas during the first year as the cask remains open (with the bung-hole topped by a loose-fitting glass stopper). The barrel is then hermetically sealed (with the corked bung to the side) and, the absorption of the wine by the wood being constant, a partial vacuum is produced that eases the transfer of oxygen through the pores of the wood. This gentle and very slight oxidation helps in the aging and improvement of the wine.

Throughout its time in the barrel, a wine progressively loses the suspended particles that it contains. By a series of decantings or "rackings" -- four times a year -- the cellar hands separate the clear wine from the lees that fall to the bottom of the casks. During the second year, the "fining" (an addition of six lightly beaten egg whites per barrel) speeds up the precipitation of particles in the wine to the bottom.

By evaporation, elimination, or absorption by the wood, about 15% of the harvest will be lost during the two to two and a half years that the wine is kept in cask.

Once the biological changes are completed, the pristine clarity achieved, the wine is ready to be bottled and, therefore, to begin a final process of extremely slow aging. This will gradually reveal, over the years, the marriage of fragrance and flavor needed for a great wine.

To learn more about wood and wine, see the cooperage of Château Haut-Brion.