Barley, after steeping in water, was ground with ease and efficiency in the Szego mill, and its starch was liquefied, saccharified and fermented to very high yields of ethanol. The Szego mill consists of vertical rollers with helical grooves which rotate within a fixed cylinder, resulting in very fine grinding and a somewhat flaky product. The steeped barley was ground to a fine paste. This was readily liquefied and saccharified by amylolytic enzymes (dual enzyme process), and the resulting sugars were fermented in 24 h by ordinary bakers' yeast Saccharomyces cerevisiae, resulting in over 450 l ethanol/t of barley. Still shorter time, 12 h, and the same high yield were achieved when liquefied barley starch was simultaneously saccharified by glucoamylase and fermented. Fermentation to ethanol by a glucoamylase-producing yeast S. diastaticus strain 164A (from Labatt Brewing Company) enabled the amount of this enzyme required for saccharification to be reduced to about one-half the normal quantity, but at some cost in slower fermentation and slightly lower ethanol yield.