A fermentation medium of brewer yeast and a method of preparing ethanol and active dry yeast by utilizing the medium

The invention relates to a fermentation medium of brewer yeast. A preparing method of the medium includes weighing distilled water and preheating the distilled water in a conical flask; weighing cornflour; fully mixing the corn flour and the distilled water; adjusting the pH value; adding a liquefying enzyme; performing water-bath heating; cooling a product; adjusting the pH value; performing saccharification, filtration, centrifugation, suction filtration and sterilization; adding (NH4)2HPO4 and KH2PO4; fully mixing the mixture; and adding distilled water to obtain the medium the initial reducing sugar concentration of which is 220 g/L. An ethanol preparing method is low in cost and short in thick mash fermentation period that is only 72 h, the utilization rate of a corn raw material isincreased, integrated utilization of crops is achieved, the ethanol yield and production benefit are increased, the cost is greatly reduced, development of clean energy is promoted and environment pollution is reduced. Yeast q