Mixing fresh silage in water resulted in partial segregation of grain from stover. Grain concentration was 75% in the sunk material when silage was relatively dry (64% moisture content [MC]) and 41% when silage was relatively wet (74% MC). Partial drying to remove 20 percentage units of moisture prior to water separation increased grain concentration to 92%, and complete drying increased grain concentration to 99%. Sieving without drying followed by water separation resulted in a grain concentration of 79%. A byproduct of water separation is a large amount of soluble and deposited fine particles in the effluent: 18% of original dry matter after one separation, and between 21 and 26% after eight separations. In an industrial setting, hydrodynamic separation of silage with minimal pretreatment could provide a feedstock with a high concentration of grain (75-80%). In a laboratory setting, hydrodynamic separation with prior oven drying could provide a method to separate grain from stover in corn silage by reaching a grain concentration higher than 99%.