The Code of Federal Regulations (CFR) lists 13 emulsifying salts (ES) for pasteurized process cheese. Commercial manufacturers typically use a blend of ES to achieve a desired textural profile. Although it is known that ES act by changing the mineral equilibrium causing micellar dissociation, there are unexplained differences between specific ES. The aim of this study is to measure the effects of combinations of disodium phosphate (DSP), tetrasodium diphosphate (TSPP), sodium hexametaphosphate (SHMP), dipotassium phosphate (DPP) and trisodium citrate (TSC) on casein micelle stability in response to changes in temperature, pH, time, and emulsifying salt concentration ([ES]). Binary ES stock solutions were made in mM concentrations of 0:200, 50:150, 100:100, 150:50, and 200:50 in a 1-in-20 dilution of protein free serum (PFS) (3 kDa MWCO) in water. ES solutions were mixed with more diluted PFS to achieve total [ES] up to 198mM. Skim milk was added to make up 2% of the volume, and turbidity was measured at 400 nm immediately (t = 0s), after 30 s and after 30 min. ES solution, milk and diluted PFS solutions were pH-adjusted before measurement to either 5, 5.8, or 6.8. Duplicate measurements were conducted at room temperature and 50°C. Data were modeled using an exponential decay equation to calculate a threshold [ES] (Ct) that caused a rapid decrease in turbidity. When ES were combined, the resulting turbidity curves displayed characteristics of both individual ES curves. Increasing the interaction time universally decreased the Ct, while increasing temperature increased average system turbidity. As the ratio of the ES was varied, the resultant curve most closely resembled the curve of the highest [ES]. For example, when DSP and TSPP were mixed at room temperature, pH 6.8, and t = 0, the Ct was 8.8 mM for 150mM TSPP and 50mM DSP, however when the [ES] were reversed, the Ct increased to 59 mM. After displaying a decrease in turbidity when [TSPP] was increased to 50 mM (from 0.688 to 0.144 AU), turbidity increased (to 0.2785 AU) as [TSPP] increased to 198 mM, suggesting temporary aggregate formation not strongly observed when [SHMP] was increased.