Abstract: A process is described for treating an approximately neutral fluid milk composition, including milk protein concentrate and milk plus added whey, by selecting an alkali, adjusting the pH upward, heating, cooling, selecting an acid, and adjusting the pH down before ultrafiltering and, in a more preferred process, thereafter diafiltering the treated composition. Selection of the appropriate alkali, pH values, temperatures, acid, and membrane filter porosity results in improved yields of retentate proteins having selected compositions with improved utility, including a more palatable flavor, a brod range of solution viscosities, an increase in the solubility of the dried retentates in cold water to nearly 100%, and an increase in the calcium content of the membrane filtered retentate by about 50% compared to a similar retentate from standard milk.