Danoss said:
But are they single malts or blends of them?
Buffalo Trace is a "small batch" whisky ala Knob Creek. What constitutes a "small batch" can change from distiller to distiller, but if memory servers, its around 200 barrels for BT. So BT can be thought of as a blend of selective batches of whisky. So the nuances of its taste can change from year to year (or months to months), like a single malt. So to answer your question, it isn't quite either.
But whether or not something is a blend or a single malt doesn't determine whether its
whisky. Plenty of whiskies are blended, plenty of scotch is blended - i.e. the whole Johnny Walker line. Some bourbons come from single barrels (ala single malts). Most single malts are selective "blends" of the same type of malt (e.g. "single"), that's part of the master distiller's job, making sure the whisky stays consistent from year to year, mixing when necessary. I think the main thing single malts
aren't doing that blends do, is blending whiskies from disparate years, say a 12 year and 3 year. [Edit: I double checked this and the answers I found suggested the distinguishing mark of a "blend" is whether or not it comes from more than one
distillery and blends also
tend to consist of some grain whereas single malts don't. Hey, learned something new.]
Traditionally whisky has either been barley, rye, wheat, or corn based. I suppose any starch that was barrel aged for the requisite amount of time could be a whisky, so long as it was processed the same in all other respects. I'm not certain, but I believe its rather a matter of contingency that whiskies came to be barley, rye, wheat, and corn based - since those were readily available and good for distilling, but I'm just conjecturing.
Bourbons only have their name because they were whiskies made in "Bourbon county" Kentucky. They are still "bourbon whiskies" though.
Feel free to correct me if I went astray at any point in time, I think the above is pretty accurate but I'm not 100% sure, especially when it comes to the single malt/blend distinction. I also think there are some exceptions making these classifications difficult.