This invention is directed to an acidic beverage composition, comprising; (A) a hydrated protein material having a combination of an inositol-6-phosphate content, an inositol-5-phosphate content, an inositol-4-phosphate content and an inositol-3-phosphate content of less than 8.0 μmol/g, with (B) a hydrated protein stabilizing agent and (C) at least one acid comprising a fruit juice, a vegetable juice, citric acid, malic acid, tartaric acid, lactic acid, ascorbic acid, glucono delta lactone or phosphoric acid, wherein the acidic beverage composition has a pH of from 3.0 to 4.5.