Lots to unpack here. The basics, according to Encyclopedia Britannica:
Whiskey (or whisky) can be any of a variety of distilled liquors that are made from a fermented mash of cereal grains and aged in wooden containers, which are usually constructed of oak. Commonly used grains are corn, barley malt, rye, and wheat.
The difference between whiskey and whisky is where the stuff is made: in the United States and Ireland, it’s spelled “whiskey”; in Scotland, Canada, and Japan, it’s “whisky.”
Whiskey vs. Whisky ✅
Now, for the differences between Scotch, bourbon, and rye. Back to Encyclopedia Britannica:
Scotch is a whisky (no e) that gets its distinctive smoky flavor from the process in which it is made: the grain, primarily barley, is malted and then heated over a peat fire. A whisky cannot be called Scotch unless it is entirely produced and bottled in Scotland.
Bourbon, a whiskey that was first produced in Kentucky, U.S., uses at least 51% mash from corn in its production. It also uses a sour mash process—that is, the mash is fermented with yeast and includes a portion from a mash that has already been fermented. U.S. regulations specify that in order for a whiskey to be called bourbon, it must be made in the United States.
And rye whiskey? It’s a whiskey that uses a rye mash or a rye and malt mash. In the United States, regulations stipulate that the mash must be at least 51% rye in order for it to be called rye whiskey. In Canada, regulations do not specify a minimum percentage of rye.
Flavor-wise, Scotch is smoky, bourbon is sweet, and rye is more astringent than the two others, making it particularly suitable to cocktails.
Scotch vs. Bourbon vs. Rye ✅