It is French oak, the wood which is used exclusively for Cognac and Armagnac barrels , which gives these brandies their special character. For Cognac, oaks from either the Tronçais forest (planted by Colbert to provide the wood needed for the construction of Louis XIV’s warships) or the Limousine forest are used. The tannins of the former are reputed to be particularly smooth, whereas those of the latter are known for the strength and balance which they give to the Cognac. A brandy kept in “Limousin-type” oak barrels can extract more tannin.
For Armagnac, oaks are also taken from the Limousin forests, but especially from those close to Gascony.
Barrels that will hold Cognac for several decades can only be made from oak trees which are more than 100 years old. Obtaining the best brandy in the world is a matter of time, a long time.