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.