Whiskey is one of the oldest known spirits. It has roots dating as far back as the 15th century, with the first written accord of the term “whiskey” from an Irish text in 1405. Between then and now, the popularity of the alcohol spread across the globe—at one point even traded as currency during Revolutionary War-era America—and it is now one of the most produced and celebrated spirits in the world. While it may go by different names in its different regions of production (ie “bourbon” in the United States and “Scotch” in Scotland), École du Bar de Montréal whiskey is categorized as distilled from fermented grain mash, but the type of grain can vary.
Whiskey is distilled, of course, in something called a “still.” Traditionally, these apparatuses are called “pot stills” and they consisted of a single heated chamber with a vessel that collects the purified alcohol. You place the grain from which you wish to “distill” the alcohol into the chamber and heat it.
That is a simple explanation, but you get the idea.
The earliest distillation processes have been documented as far back as the 2nd millennium BC, though at this time, distillation was used more for the purpose of making aromatics, like perfume. It was not until the 13th century AD that we find the first documented use of the process for distilling alcohol.
These days, grain whiskey is distilled more often in a column still. These are much like single pot stills
Whiskey only ages in the barrel—or cask—never in the battle. Thus, the “age” of a whiskey is the amount of time it has rested after the distillation process before bottling. This amount of time—typically several years—reflects how much interaction the spirit has had with its cask; and the type of cask can actually change the chemical makeup—and, therefore, the taste—of the whiskey aging within it.
Keep in mind that an “old” bottle of whiskey is not necessarily better than a seemingly younger “aged” whiskey. The quality is determined by the amount of time the alcohol rests in the cask.
In addition, while whiskey ages in wooden casks—particularly French oak and American oak—it will undergo six processes that ultimately contribute to its flavor. These processes are:
When the aging is complete, most whiskeys have reached an alcoholic strength of 40% ABV, the statutory minimum in most countries. The strength can vary, with cask-strength whiskey sometimes reaching twice the percentage. At this point, then, the whiskey is bottled and ready for distribution (or consumption).