in one aspect of the invention , a method recovers oil from a concentrated byproduct , such as evaporated thin stillage formed during a dry milling process used for producing ethanol . the method includes forming a concentrate from the byproduct and recovering oil from the concentrate . the step of forming the concentrate may comprise evaporating the byproduct . further , the step of separating the oil from the concentrate may comprise using a centrifuge and , in particular , a disk stack centrifuge . other aspects of the invention include related methods and subsystems for recovering oil from thin stillage .