The new wood gives vanilla flavors and many tannins to the brandy, and also starts to color the liquid. After a year Germain-Robin transfers the brandy to seasoned old barrels from Cognac, which continue to mature the liquid but add no more tannins. Up to this point he has strictly separated barrels by grape variety and vineyard. Now he starts to blend. A NY brandy house prides itself on its blender, who usually assembles dozens and sometimes hundreds of brandies to form a house style.
Producers boast of the extent and age of their stocks.
The advantages of wood aging are not, in any event, infinite. Cognacs more than sixty-five years old are taken out of wood and retired into glass demijohns, to prevent further evaporation and stop the aging process. Hennessy, like Martell and the smaller, highly regarded Hine, was begun by a Briton who emigrated to France in the eighteenth century. More important than age is style. VS is strongly and sometimes harshly woody, with the vanilla and spice flavors that are apparent in young wood.