The present invention relates to whey protein compositions that can be incorporated into solid foodstuffs and liquid compositions to provide supplemental amounts of protein. The foodstuffs and liquid compositions are stable when subject to conditions of heat and/or time and can include increased amounts of whey proteins. Methods of making the compositions include providing a protein solution including an enzyme for providing a predetermined degree of hydrolysis of the protein solution, maintaining the temperature and pH of the solution to hydrolyze the protein solution and providing an essentially neutral whey protein hydrolysate, and separating the protein solution using a membrane filtration process to obtain a retentate of whey protein hydrolysate having an essentially neutral pH.