A method of hydrothermally treating stillage by heating stillage to 200 degrees F. to 350 degrees F., altering physicochemical properties of the stillage, enabling facile separation of the stillage, and creating unique product fractions. A method of performing ethanol fermentation by treating stillage to enable facile separation by heating the stillage to a temperature of 200 degrees F. to 350 degrees F., and separating the treated stillage to recover a high protein solids fraction, a stickwater fraction, and an oil fraction. A method of improving fermentation by heating stillage to a temperature of 200° F. to 350° F. resulting in hydrothermally treated stillage, using all or a portion of the hydrothermally treated stillage as a component of a media, and using the media for a process including fermentation and biomass production. Oil, stickwater, high protein solids fraction, high protein meal, metabolites, biomass, and media obtained from the methods above.