Cognac is a prestigious brandy drink that can be produced solely in the French Cognac region from a blend of eaux de vie - “water of life”, pure distillate of grapes produced after double distillation in special copper boilers. In order to be named Cognac, the distilled alcohol must undergo an aging process of at least two and half years, then to be merged with eaux de vie from different barrels and then diluted with distilled water to lower the alcohol level to 40%. Cognac's age is determined by the age of the youngest cognac added to the blend.
A little bit about Cognac
There's a special comittee in France called "comité de cognac" which oversees the manufacturing and aging processes of all Cognac brands, and verifies that a certain standard of overall quality is maintained.