The present invention pertains to a method of producing beta-casein-containing compositions and products obtainable by such methods. More particularly, the invention pertains to a method of producing beta-casein compositions using controlled microfiltration first at a temperature higher than 20 degrees C., followed by cooling of the retentate to 0-15 degrees C. and a second microfiltration of the cooled composition resulting in beta-casein containing permeate.