The agglomeration of a powder mixture which is commonly used to make granules containing enzyme was examined in a high shear mixer granulator of the Lodige type. The validity and extension of current granulation theory for practical high shear granulation was investigated. The effects of process variables such as the amount of binder liquid, chopper impact, binder viscosity and temperature on the granulation were in agreement with the theory. The onset of the different granulation mechanisms (nucleation, compaction, coalescence, and crushing and layering) was demonstrated.