What exactly makes something taste good or smell bad?

Question

What exactly makes something taste good or smell bad?

Answer 1

The Tongue or the nose

Answer 2

douching or not douching.

Answer 3

Different chemicals react with different receptors in your tastebuds and nose.  When these receptors are activated, it stimulates a nerve connected to the associated bit of your brain whose job it is to report that something tastes salty, or smells fishy, or whatever.