Emulsifying salts (ES) are essential in processed cheese (PC) manufacture, providing a uniform structure and desirable properties. This study investigated the effects of ES type—anhydrous disodium hydrogen phosphate (ADSHP), monopotassium phosphate (MPP), potassium–sodium tartrate tetrahydrate (PSTTH), dipotassium tartrate hemihydrate (DPTHH), trisodium citrate dihydrate (TSCDH) — and concentration (0.5–2.5% w/w) on the texture, spreadability, rheological, and melting properties of model PCs formulated with acid casein and whey protein concentrate. Increasing ES concentration led to higher hardness, adhesiveness, and viscosity, while spreadability decreased (<2.5% w/w ES was sufficient). The highest storage modulus values were observed at 2.5% w/w ES and were associated with increased hardness and adhesiveness. All samples exhibited high springiness, cohesiveness, and good meltability (Schreiber score >4). Among ES types, PSTTH and DPTHH produced the most desirable texture, rheological properties (hardness, adhesiveness, cohesiveness, springiness, G′, tan δ) and adequate meltability, whereas at 0.5–1.5% w/w yielded optimal spreadability.