A number of samples of commercially available spray‐dried and roller‐dried caseinates have been compared with freshly prepared caseinate from the laboratory. The compositions of the materials were measured using chromatography, and their calcium susceptibilities were determined using turbidity measurements. The chromatographic analysis showed that the commercial caseinates differed substantially from the fresh material, especially in the regions where α‐casein and αs2‐caseins were eluted. The fresh caseinate was more affected by the presence of calcium ions than the others, and there were also differences between the individual spray‐dried caseinates in this respect. The roller‐dried caseinates were very insensitive to the presence of