Bottled-in-Bond is a designation that refers to American whiskeys (and some brandies) that are distilled, aged, and bottled entirely at one distillery, from barrels filled in one season, by one distiller. Furthermore, the whiskey must be four years old and bottled at precisely 100 proof. In the old days, this was a way to protect the consumer from brands that were merely bottling up whiskey from other distilleries and blending or adulterating that whiskey.