The milk at pH 4.5 may produce a refined casein, a surrogate of rennet casein.

A method for obtaining beta casein involves using rennet casein, for example as produced by the enzymatic curdling of milk, wherein the kappa casein is hydrolyzed to form para kappa casein.

Disodium diphosphate is added to rennet casein as a food preservative and to make certain foods edible.