Throughout this blog, I've been using both spellings interchangably, but this kind of inconsistency drives me crazy. So, here's the word from Wikipedia (which also matches what I've read elsewhere):
The spelling whisky (plural whiskies) is generally used for those distilled in Scotland, Wales, Canada, and Japan, while whiskey (with an e; plural whiskeys) is used for the spirits distilled in Ireland and in the United States as well. A 1968 BATF directive specifies "whisky" as the official U.S. spelling, but allows labeling as "whiskey" in deference to tradition, and most U.S. producers still use the latter spelling. A mnemonic used to remember which spelling is used is that "Ireland" and "United States" have at least one "e" in their names, while "Scotland," "Canada" and "Japan" do not. International law reserves the term "Scotch whisky" to those whiskies produced in Scotland; Scottish law specifies that the whisky must be aged for a minimum of three years, in oak casks. Whiskies produced in other countries in the Scotch style must use another name. Similar conventions exist for "Irish whiskey," "Canadian whisky," and "Bourbon Whiskey." In North America, as well as in Continental Europe the abbreviated term "Scotch" is usually used for "Scotch Whisky." In England, Scotland, and Wales, the term "Whisky" almost always refers to "Scotch Whisky", and the term "Scotch" is rarely used by itself. The Welsh version is wysgi (though the forms chwisgi and wisgi also exist).
So there, more than you ever wanted to know. I will try to use the correct spelling depending on which country produced the stuff and will use the whisky spelling for the generic in deference to the original. Besides, I'm an American and Lord knows I'd hate to run afoul of the BATF... Guns, alcohol, and tobacco. My guys.
You can all rest easy tonight.