Date of this Version
Crude amylase preparations were produced by growing Aspergillus awamori and A. niger on raw, ground, whole corn. These Koji preparations were used to hydrolyze the starch of raw, ground whole corn to sugars during simultaneous fermentation of the sugars to ethanol by distillers active dry yeast. Ethanol concentrations of the fermentation beers were determined with gas-chromatography. These fermentations yielded an average of 89.6% theoretical ethanol compared to control, conventional, fermentations that had an average of 89.9%. Carbon dioxide evolutions were determined with use of Alwood valves. The initial fermentation rate was greater for the conventional fermentation than the Koji fermentation. However, both fermentations produced 0.48 g of carbon dioxide per gram of dry substrate starch within 72 h. Koji dehydrated at 41 °C had no apparent detrimental effects on theoretical ethanol yield.