For the chemist, sweet taste perception must begin with the simple pri
nciples of chemoreception. Molecules endowed with an appropriate 'Gluc
ophore' are able to interact with, and elicit a response in, a putativ
e receptor. The challenge is thus to explore the structures of sweet m
olecules, their modification in the environments in which they are pre
sented and their access to, and activation of receptors. A recent appr
oach to structure-activity relationships in sweeteners has centred on
the role of water. This has led to a clearer picture of the real hydra
ted state of sweet molecules and differences between them based on the
ir solution properties. The role of water is of particular relevance i
n beverages and offers the tantalising prospect of sensory control of
formulations based on objective solution measurements. Parameters such
as H-1 NMR pulse relaxation times, intrinsic viscosities and apparent
specific volumes can be compared to evaluate the solution behaviour o
f sweet molecules. Apparent specific volumes offer direct experimental
verification of computed volumes and, more importantly, are measures
of the effective volumes of sweet solutes in the vicinity of receptor
sites. They have already been shown to be broad determinants of taste
quality. Sweet molecules belong to vastly different chemical classes a
nd they elicit different qualities, intensities and persistences of re
sponse. Future progress in the optimisation of sweet taste perception
may lie in enhancement or inhibition of the response and control of so
lution interactions