Abstract: Disclosed is a dry or wet milling process for making fermentable sugars and high-protein products from starch bearing material, characterized by saccharification of the starch followed by recovery of fiber and other non-protein materials and of destarched protein as separate products, leaving a sugar solution that is essentially free of insoluble materials. The sugars are fermented to ethanol and carbon dioxide by the action of added yeast. After fermentation, the yeast is recovered for use in fermenting additional quantities of sugars supplied either for batch or continuous processing. The alcohol is then removed leaving a dilute solution of unfermentable soluble materials, and this liquid, in whole or in part, is recycled to preceding steps in the process.

Abstract: In the production of ethanol in plants, comprising a fermenter, a centrifugal separator for the recirculation of the yeast to the fermenter and a plant for the separation of a yeast-free flow, coming from the centrifugal separator, into one flow, rich in ethanol, and into one residual flow, the substrate, that is fed to the fermenter must be rid of solid substance, like fibres etc. In the separation of such solid substance a certain amount of substrate has been lost according to the methods utilized hitherto, or an unnecessarily high consumption of water and energy has occurred. According to the invention the solid substance, which is separated from the raw material flow, is washed, preferably countercurrently with said residual flow, which in turn, enriched in substrate, is fed to the fermenter. If a distillative method is used for said separation the residual flow is called slop.