This is a process to make a shelf-stable, liquid, ready-to-drink, asepticnutritional formulafor the treatment of PKU, tyrosinemia or other errors of metabolism. Theliquid nutritionalformula has caseino-glyco-macropeptide as the primary protein source andcomplementaryessential amino acids to complete the requirement profile. The beverage alsoincludes vitaminsand minerals sufficient to meet daily requirements. When used as a completediet, the nutritionalformula includes a carbohydrate source and a fat source. The nutritionalformula has a pleasanttaste.