Nowadays it is quite easy to overlook Canadian Whisky in a globalised liquour store. There are a mere handful of producers and even fewer are recognised brands with decent exports. Over the course of the 19th and 20th centuries Canada was a large force in the whisk(e)y world yet not so much anymore.
How did Canada come to produce Whisky that was for a large portion of time very famous, you ask? Well, the Scots came over and eventually immigrated to Canada over the course of the 18th century as a retreat from Scotland. With an uptake of Scottish immigrants it was only a matter of time before Canada handed over its first whisky distillery licence. This happened in 1794 - initially for a Canadian version of Rum. It wasn't until the mid 1820s when a variation of whisky can to be in Canada. From here on in the marketplace boomed with distilleries popping up all over the place. The largest boom for Canadian whisky came with America's prohibition and the illegal smuggling of goods across the border. Many a shoot-out in the 1920s had a case or two of Canadian Whisky in the balance - the most famous of which is, of course, the Valentine's Day Massacre.
One of the most wonderful aspects of producing Canadian whisky from the points-of-view of the distillers is that there are only two rules: 1) that the whisky must be distilled in Canada in order to be labelled as such, and 2) the resulting whisky must be aged in oak for at least two years before bottling. Easy enough! Outside of this fairly obvious rule the whiskies produced can be made out of a range of starches from corn, barley to rye, and can be distilled and aged in a variety of ways.
Traditionally the grain used as the base of Canadian whisky was rye. This was due to it being the only hardy enough crop to deal with the severe winters. Over time more and more corn has been imported and produced in Canada and this is now the main grain used for distilling. Most Canadian whisky are blends and blends of up to 40-50 different whiskys all of different attributes. As there are so many different potential styles able to be produced the distillers have numerous combinations to work with.