Oak barrel is the specific vessel for storing wine, since oak is not only tough and tensile and non-perishable, but also has sound gas permeability, which is beneficial to wine breath. The oak essence in oak barrel endows wine with one of or all fragrances of vanilla, coco, and coffee. Special substance in oak can reduce the astringency of wine, making it soft and gentle; can make brandy change from colorless to golden yellow or amber or make brandy’s taste change from spicy to smooth and mellow.