The functional properties of low-moisture part-skim (LMPS) mozzarella are pivotal for its commercial application, e.g. as pizza topping. We previously investigated the variations in the functional properties of LMPS mozzarella manufactured on different days using a standardized procedure during 1 month of storage at 4°C. However, we did not investigate the variations in the functional quality of LMPS mozzarella stored for more than 1 month at 4°C. The time allocated to transport, processing and storage of the cheese may be longer than 1 month. Moreover, we did not investigate the influence of other sources of process-related variability, such as the use of alternating cultures, coagulants, or other adjustments to the cheese manufacturing procedure. The current study therefore investigates the variability in LMPS mozzarella characteristics sampled at monthly intervals over a 1-year period from an industrial cheese plant during 4 months of storage at 4°C. One hundred-and-fifty cheese blocks were procured from 50 vats, held at 4°C for 0.5, 2, 3 or 4 months and assayed for composition, primary proteolysis, texture profile analysis, heat-induced changes in viscoelastic behavior, cheese extensibility and flow. The results revealed differences in the functional quality between cheeses obtained on different sampling occasions after 0.5, 2 or 3 months of storage. A linear model revealed that the variability in the functional performance was not only affected by storage time, but also by differences in cheese composition, and by several interaction effects. The results further demonstrated that the impact of process-related variations in cheese composition on the solubilization of colloidal Ca or the flow of the heated cheese outweighed that of storage time after 14 d. This study may therefore offer commercial manufacturers with clearer insights in the quality consistency of their cheese after its release into the market.