A stillage clarification process and related system include using hydrocyclones and high recovery disc centrifuges for fractionation of stillage from a grain ethanol plant and splitting the stillage into fractions with mass and compositional assays per bushel of grain processed. The fractions include a first fraction comprising 45% to 70% protein and 3% to 8% fat, a second fraction comprising distillers corn oil, a third fraction comprising a fiber having made up of approximately 22% to 28% protein and less than 8% fat, and a fourth fraction comprising at least 30% soluble protein and less than 3% fat.