It lends the nose a touch of complexity and amiability while respecting the nature of the fruit and of the wine, it will offer an elegant bouquet. As the wine ages, the hint of oakiness will disappear. The wine will have body and character, and the bouquet will retain its increased complexity.
The length of the maturing influences the quality of the bouquet, as does the way the barrel has been heated during fabrication (which will give off a smoky, roasted, or related flavour), as well as the quality of the oak, of course, since it acts upon the tannins.
French oak from the Vosques, the Limousin, and the Allier are reputed to be among the best, along with their American competitor, the white oak, which, while less complex and refined, still lends a certain sweetness with a hint of coconut or vanilla. It should be noted that a producer usually orders several different kinds of casks from the cooper, in order to obtain as many varied combinations of savours as possible. In general, wood adds its mark to the wine of most of the great terroirs. But it gradually disappaers, leaving room for the wines’s structure and complexity, except when the maturing in oak is too marked, in which case the wine ends up vaguely resembling an English breakfast, with hints of toasted, roasted, torrefied or a smokiness. But there is worse: when the wine ages in barrels that are too old or dirty, or of mediocre quality, its maturation is down right vulgar. Because of their capillarity, the defective barrels naturally pass all their negative qualityies such as oxidation and volatile acidity (a vinegary odour) on to the wine.
There are exceptional wines, extremely pure and mineral, with scents of flowers and fresh fruits, which are rich in elegant structure, light and refreshing, that have been never known a single moment of contact with wood. There are many very young wines dominated by new wood, with a touch of the roasted aromas and scents of vanilla that are less than subtle to perceive. These widely-commercialised products hide the true perfume of the wine.