TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The method further comprises introducing the additional enzyme or enzyme cocktail to the whole stillage, thin stillage and/or syrup, mechanically pretreating the mash or feedstock with a high shear rotor stator device. The additional enzyme or enzyme cocktail is added to the thin stillage stream. The additional enzymes are dosed at a rate of 0.05-0.75 ml of enzyme solution per liter of thin stillage. The viscosity of the thin stillage or syrup stream is reduced by 10%. Preferred Components: The additional enzyme comprises xylanases, beta-glucosidases and/or arabinofuranosidases. The additional enzyme or enzyme cocktail consists of debranching enzymes, hemicellulases, pentosanases, xylanolytic enzymes, exoxylanases, endoxylanases, glucanases, exoglucanases, endo-beta-1,4-xylanases, exo-beta-1,4-xylosidase, alpha-L-rabinofuranosidase, endo-alpha-1,5-arabinanase, glucuronidases, alpha-glucuronidase, mannanases, endo-beta-1,4-mannanase, exo-beta-1,4-mannosidase, alpha-galactosidase, endo-galactanase, xylosidases, acetylxylan esterases, glycosidases, beta-1,4-glycanases, pectinases, polygalactoronases, esterases, amylases, phytases, peroxidases, laccases, glucose oxidases, oxidoreductases, lipases, lipolytic enzyme, proteolytic enzymes, and/or proteases. The cellulase enzymes are added to the fermentation tank. The rotor stator device has a gap (0.10-0.75 mm) between the surface of the rotor and the stator. The mechanical pretreatment produces particles such that the majority of particles have a particle size of 100-1000 mu m. The majority is greater than 85 wt.% of the total non-dissolved solids in the mash. The non-cellulosic sugars comprise starch derived from corn kernels, wheat, milo, sorghum, rice, maize, barley, and/or sugar beets. The cellulosic sugars are derived from corn kernel fibers or corn kernel fibers plus other cellulosic feedstock comprising corn stover, paper or paper sludge, reprocessed paper or cardboard wastes, stalks, wood waste, or other low starch feedstock, and comprise less than 40 wt.% of the total hydrolysable polymeric sugars in the feedstock. The other cellulosic feedstock is preprocessed by a pretreatment step before adding the cellulase enzymes to the feedstock.