Disclosed is a method for reducing the viscosity of a product containing casein micelles, the method comprising a) applying carbon dioxide to an aqueous product comprising casein micelles to reduce the pH of the product b) increasing the pH of the product and c) collecting the product comprising casein micelles, in which at least some of the casein micelles are modified in structure by one or more of steps a) and b) compared to naturally occurring casein micelles, which product has reduced viscosity compared to that of the aqueous product. Also disclosed are methods for reducing rehydration time and for increasing the concentration of a product containing casein micelles.
