Whisky has its roots in Ancient Babylon and Mesopotamia, but it was Christian monks who are believed to have brought distillation techniques to Ireland and Scotland. The spelling differs in the US where its known as Whiskey, but the very popular beverage is crafted across the world from various grains including barley, corn, rye, and wheat; with connoisseurs very loyal to their dram of choice from Scotland and Ireland. Kentucky Bourbon and Japanese Whisky also make an indelible mark. Typically aged in charred white oak wooden casks, the age of a Whisky is identified by the time between distillation and bottling.