We discuss the perception of grittiness in the human mouth from the perspective of continuum mechanics and draw some conclusions about the likely interactions between hydrodynamically arising stress fluctuations and stimulation of biological mechanoreceptor structures. Two classes of mechanoreceptors exist, responding to either static or dynamic stresses. It is apparent that the static stresses arising from inclusions are very small relative to the background stresses generated by the squeeze flow unless the inclusion is very close to either the palate, tongue or free surface. The situation for dynamical stress fluctuations in less clear.