This invention is directed to an acid beverage composition having a pH of from 3.0 to 4.5 having (A) a hydrated protein stabilizing agent; (B) at least one flavoring material; and (C) a slurry of an aqueous protein material prepared by a process including preparing an aqueous extract from a protein containing material, adjusting the pH of same to precipitate the protein material, separating the precipitated protein and forming a suspension of same in water, adjusting the pH of the suspension to a particular pH value, and pasteurizing same.