Embodiments of the invention relate to whey protein compositions that can be incorporated into food or beverage products that provide supplemental amounts of protein. The acidified whey protein compositions of the present invention may comprise a liquid whey protein and an acidulant. The liquid whey protein and the acidulant may be blended, and the resulting composition may then be co-dried. The acidulant may be present in an amount effective for reducing the pH of the composition prior to drying to a value less than about 6. Embodiments of the present invention also include methods of preparing co-dried acidified whey protein compositions exhibiting improved organoleptic characteristics.