In any château estate there is a subterranean region: the wine cellar. Estate cellars are extremely vital in determining the character and quality of the fine wines. The wines are left to develop gradually in carefully planned conditions and this is what brings about complexity and depth.
When the young wine is moved into barrels or storage vessels the aging of wine starts and it continues after fermentation. Oak barrels are used in many chate estates and this has a slight change of the taste profile of the wine. The notes produced by oak aging include vanilla, spice and toasted wood as well as controlled oxygen access which softens tannins.
The cellars of the estate require temperature and humidity regulation. Optimum conditions ensure that there is constant temperature to avoid untimely aging or spoilage. Humidity also acts to maintain cork integrity, and thus corks when the bottles have been stored over a long period of time.
Old style chate cellars are usually constructed below ground with the use of stone or bricks. These are materials that are naturally the temperature regulators and produce a stable environment to age wines. A visit to such cellars will give the visitor an idea on how much patience and craftsmanship goes into the production of wine.
One of the stages is barrel aging.