there are 3 phases to a alcohol distillation, the first part, called the heads (some people further divide this up into two more categories, but we will not get into that) contains most of the methanol and ethyl acetate. Every distilliation gets rid of that fraction, because it will make you sicker than sick
The next part to come off the still is the ethanol fraction This is for the most part pure ethanol and water. This is what is kept for the largest proportion of all distillations.
That last bit is the tails. The tails contain things like isopropanol (rubbing alcohol) and other fuesel alcohols that are part of the certain fermentation and are dependant on the starting material. Different whiskeys keep a differnt proportion of these to give the whiskey flavor. That is why scotch still retains some of the smoked malt character, and burbon keeps the corn character and why neither tastes like canadian whiskey which does not keep any of the tails and has no character of the starting material. That is also why Rum and tequilla have their specific flavcors and why none of them taste like vodka. Vodka is basically a neutral spirit. you can make vodka from anything because you do not keep any of the tails involved with them. Canadian whiskey keeps very little of the tails and then ages it in charred oak for some flavor and color.
