Four treatments of natural Cheddar cheese with two levels (high and low) of calcium (Ca) and phosphorus (P), and two levels (high and low) of residual lactose were manufactured. Each treatment was subsequently split prior to the salting step of cheese manufacturing processed and salted at two levels (high and low) for a total of eight treatments. The eight treatments included: high Ca and P, high lactose, high salt-in-moisture (S/M) content (HHH); high Ca and P, high lactose, low S/ M (HHL); high Ca and P, low lactose, high S/M (HLH); high Ca and P, low lactose, low S/M (HLL); low Ca and P, high lactose, high S/M (LHH); low Ca and P, high lactose, low S/M (LHL); low Ca and P, low lactose, high S/M (LLH); and low Ca and P, low lactose, low S/M (LLL). After 2 months of ripening, each treatment of natural Cheddar cheese was used to manufacture processed cheese using a twin-screw Blentech processed cheese cooker. All of the processed cheese food formulations were balanced for moisture, fat and salt. Texture and melt-flow characteristics of the processed cheese were evaluated with different techniques, including texture profile analysis (TPA) for hardness and melt profile analysis. There was a considerable increase in cheese hardness for the processed cheeses prepared from high Ca and P content, and high S/M natural cheeses compared with low Ca and P content and low S/M natural cheeses. Moreover, definite decrease in flow rate and extent of flow was observed for processed cheeses manufactured from high Ca and P content, and high S/M natural cheeses than that of low Ca and P content and low S/M natural cheeses. No considerable trend was observed in hardness and melt-flow characteristics for the processed cheeses manufactured from high and low residual lactose content natural Cheddar cheeses. This study strongly demonstrates that the characteristics of natural cheese (calcium and phosphorus content, lactose content and salt-in-moisture content) used in processed cheese manufacture have a significant impact on processed cheese functionality.