Why is chocolate melting on the tongue such a decadent sensation? Why do we love crunching on bacon? Why is fizz-less soda such a disappointment to drink, and why is flat beer so unappealing to the palate? Our sense of taste produces physical and emotional reactions that cannot be explained by chemical components alone. Eating triggers our imagination, draws on our powers of recall, and activates our critical judgment, creating a unique impression in our mouths and our minds. How exactly does...