We keep saying the spelling of whiskey doesn't matter, yet we keep writing about it at great length. So does it matter or not?
How one spells whiskey doesn't matter because that's all it is, a spelling difference. It is one word that may be spelled (or spelt, if you're British) in either of two different ways. The way one spells it tends to depend on where one lives. In good writing, about the only rule is pick a spelling and stick with it.
This is all very normal, as there are dozens of English words with more than one acceptable spelling, and that is how writers and editors handle it. As there tend to be American and British spellings (the British spellings being generally followed in all English-speaking countries except the USA), it's also good form to pick one or the other spelling family and stay consistently within it.
Therefore, if one uses color, maneuver and center, one should also use whiskey.
The problem is caused by people who refuse to follow logic and instead advocate a silly, awkward, inconsistently-applied, imaginary rule that says how you spell whiskey depends on the whiskey's country of origin, and when you are talking about all whiskey or whiskey generally, you have to use some really stupid and awkward formulation such as "whiskey and whisky" or the dreaded "whisk(e)y." You also have to violate the consistency rule by switching between spellings if your discussion spans several types.
Then you have the problem of a handful of American producers who label their products "whisky."
The reason all this matters is because the country-of-origin spelling rule leads people, a lot of people, to believe that the two spellings are actually two different words with different meanings. Then those people dream up all sorts of imaginary reasons for the split. They repeat imaginary tales about frugal Scots omitting the "e" to save ink.
Then it gets pernicious.
People falsely link the spelling to the type of still used, usually defaming American whiskey in the process. They imagine non-existent international laws designed to protect the integrity of the one true "whisky," as if the absence or presence of a solitary "e" is such a powerful thing.
Their reasoning is logical if a trifle obsessive. If there is such a rule, they figure, there has to be a reason for it, so they try to intuit what that reason might be.
It matters because it perpetuates the myth that single malt scotch isn't just a type of whiskey but is the only true whiskey, and must therefore be spelled "whisky." They actually believe that all lesser whiskeys are required to bear the "e" as a mark of Cain.
The Scotch Whisky Association (notice how I respect the chosen spelling of proper names) doesn't exactly say this, but they do contribute to the problem by insisting that their product always be spelled "whisky."
The question of bourbon whiskey versus Tennessee whiskey is related, but different. The awkwardness there is that a product must meet certain legal requirements to be called "bourbon whiskey" while the law is essentially silent as to the meaning of the term Tennessee whiskey. The producers of Tennessee whiskey (there are only two) define it as bourbon that goes through an additional step of charcoal filtering before aging. Many people mistakenly believe that this step disqualifies the product from being called bourbon. That question has never been reached and I, personally, consider the proposition dubious. The fact is that the producers of Tennessee whiskey simply prefer that term, as they think it makes their product distinctive.
There are now in place international treaties that prevent the importation into the United States of any foreign-made product purporting to be either bourbon whiskey or Tennessee whiskey. Could someone make Tennessee whiskey in Colorado? They could try, but I suspect the owners of Jack Daniel's and George Dickel would raise a mighty stink. They would argue that Tennessee whiskey describes both a style of whiskey and a place of origin. Presumably, if another producer wanted to open a distillery in Tennessee to make whiskey the same way Jack and George do, that would be okay.
As with the spelling of "whiskey," the problem here is that people imagine all sorts of reasons why Daniel's and Dickel cannot be called bourbon, all of which are false. If you tick off the rules for bourbon or, for that matter, straight bourbon, the Dickel and Daniel's products meet every single one.
That leaves another little issue. Why do I always spell Tennessee with a capital "T" but generally spell bourbon with a lower case "b"? Aren't they both place names? The best way I can explain it is that "Tennessee whiskey" still uses Tennessee as a place of origin while "bourbon whiskey" does not, as bourbon whiskey is not made in Bourbon County. Although the term has its root in a place name, it no longer is used as a place name when describing whiskey. A good way to think of it is that while "whiskey" and "whisky" are one word with two spellings, "Bourbon" and "bourbon" are two different words that happen to be spelled the same way, with one being a place name and the other not.
If you think this is a lot to write (and read) about something that isn't important, then don't read it, and certainly don't waste everybody's time by writing about how it's not important. This is one of those subjects about which a lot of nonsense is written. The true facts need to be on the record, and now they are.