Skim milk powder (SMP) is an affordable option for acidic protein beverages. This application can be achieved with technologies allowing translucent dispersions with enhanced stability. The objective of the present study was to characterize SMP dispersions after dissociating casein micelles by acidification using gluconic, hydrochloric, or citric acid and subsequent heating. SMP was hydrated at 5% wt/vol in deionized water overnight, followed by acidification to pH 3.0 with gluconic, hydrochloric, or citric acid and subsequent heating at 90°C for 2 min. Samples were characterized for turbidity, hydrodynamic diameter, free calcium (Ca) ion concentration using an ion selective electrode, total Ca and phosphorous (P) concentrations using inductively coupled plasma optical emission spectrometry, zeta-potential, and transmission electron microscopy (TEM). Before heating, the SMP dispersion acidified with gluconic acid showed lower turbidity (394 NTU) than those acidified with hydrochloric (1491 NTU) or citric (1405 NTU) acid. However, this variation was significantly reduced after heating, showing 248, 431, and 599 NTU for the gluconic, hydrochloric, and citric acid treatments, respectively. The hydrodynamic diameter of dispersion decreased from 285 to 178 nm after acidification with gluconic acid and to 111 nm after heating, and no precipitation occurred after 2 weeks at 21°C. Ca and P concentrations in the serum of dispersions increased after acidification and heating. However, there was no linear correlation between the increased Ca and P concentrations and the reduced turbidity. The concentration of free Ca ions also increased from 112 mg/L before acidification to 342, 439, and 552 mg/L after acidification with gluconic, citric, and hydrochloric acid, respectively, and heating. The complex formation between Ca ions and chelating gluconate and citrate resulted in the lower measured Ca ion concentration than the HCl treatment. Heating did not affect zeta-potential of acidified SMP dispersions. Lastly, altered structure of casein micelle was confirmed by TEM. Calcium chelating acids may be used to produce novel acidic protein drinks based on SMP.