American & Canadian Spirits
When the distilling practices were brought to the Americas, so were the spellings. Those distilleries with Scottish backgrounds used “whisky”, while those with Irish backgrounds preferred “whiskey” on the label.
As a general rule of thumb, in Canada you will find “whisky” while in the United States you will find “whiskey.”
There are always exceptions of course, and it is completely legal in Canada for distilleries to label their spirits with either spelling. For example American distillers George Dickel, Makers Mark, and Old Forester all forgo the “e” on their labels, a nod to their Scottish heritage.
Related: The 11 Health Benefits of Whiskey
Interestingly enough, the Standards of Identify for Distilled Spirits, the legal regulations for spirits sold in the US, uses the “whisky” spelling, most likely because it was based on European regulations.
Meanwhile in Canada, Alberta Rye uses the whiskey spelling, as does Royal Canadian and Mount Royal Light.
So, does Whiskey vs Whisky really Matter?
Some whisk(e)y aficionados (snobs?) may tell you that the spelling matters. To be fair, there is far too much usage of either spelling now to really allow for a distinction to be made in North America.
In general when referencing these spirits, try to use the spelling that the brand uses, and any mistakes will be overlooked.
In the United States, there is no distinguishable difference between American whiskey and whisky. When referring to a group of distilleries that includes Makers Mark, the spelling whiskey is 100% acceptable.
When the whiskey vs whisky spelling really matters is when you’re writing about Scotch Whisky and Irish Whiskey. Using the proper spelling for these spirits at least makes a lot more sense given the historical usage, and the consistency of use in the two countries.
All that should really matter in this whiskey vs whisky debate that the whisk(e)y tastes delicious.