This invention is directed to a process for preparing a stable suspension of a protein material in an acidic beverage, having;blending (A) a hydrated and homogenized protein material slurry with (B) a hydrated protein stabilizing agent-acid dispersion, and pasteurizing and homogenizing the blend. In an alternative embodiment, the invention is directed to a process for preparing a stable suspension of a protein material in an acidic beverage, having;blending (A.sup.1) a hydrated and homogenized protein material-protein stabilizing agent slurry with (B) a hydrated protein stabilizing agent-acid dispersion, and pasteurizing and homogenizing the blend.