Whey protein materials such as whey from cheese making processes, whey protein concentrates, and whey protein isolates, are deflavored by adjusting the pH of an aqueous composition of such whey protein materials to about 8 to about 12 to solubilize the whey proteins and to release the flavoring compounds and thereafter passing the pH-adjusted composition to an ultrafiltration membrane having a molecular weight cutoff up to about 50,000 Daltons under conditions at which the flavoring compounds pass through the membrane, leaving the retained whey protein material with improved flavor.