ABSTRACTA modified deformation theory for the parallel‐plate plastometer, with empirical assumptions that the material obeys the “power law” and that elastic components are negligible, appears to apply to chewing gums of varying degrees of subjective staleness. Data for apparent viscosity correlate with panel perceptions of initial hardness of chew.Thickness‐time curves generated in plastometer tests can be fitted by either of two different algebraic functions whose constants also reflect the subjective hardness. These equation constants vary in a regular way with changes in the forces employed for deformation so that comparisons under different test conditions are faci