Sweet taste is a major determinant of apple fruit as driving a large part of consumer preferences. As a consequence, increase in sweetness is very frequently one of the targets in breeding programs and is a key parameter for evaluating apple quality. Its perception can be modulated by several factors, and it is important to understand the individual impact of each of them and the processes involved in order to interpret it better.This chapter reviews the studies of the past two decades dealing with apple and specifically its composition and the related sweet perception. It proposes an M. Charles (*) BIOFORTIS Sensory and Consumer,