>>718047447
First is fumes. Generally, cheap bottom shelf spirits do not cut the heads and tails as much, leaving in more ethyl alcohols. the liquor will have strong vapors and will burn like fire. This is done intentionally with some spirits to give them a 'home-distilled' or 'rustic' feel, but with whiskey the only time anyone would intend that would be with rye whiskey reminiscent of moonshining.
After that, the difference between middle and expensive whiskey is all of the flavors that arent the whisky. Whiskey that is aged for years in charred barrels, absorbing the flavor of peat and the oak and added spices like cinnamon and cloves or wood chips from cherrywood or applewood or maplewood, gains deep notes of those flavors. Cheap whiskey tries to add these flavors as well, but generally it comes across as the difference between the smell of freshly baked apples versus the smell of a "freshly baked apples" scented candle.
