FUEL ALCOHOL PRODUCTION - OPTIMIZATION OF TEMPERATURE FOR EFFICIENT VERY-HIGH-GRAVITY FERMENTATION

The time required to end ferment wheat mash decreased as the temperatu re was increased from 17 to 33 degrees C, but it increased as the conc entration of dissolved solids was raised from 14.0 to 36.5 g/100 mi. E thanol yield was not appreciably affected. Over the range of fermentat ion temperatures tested, the addition of urea accelerated the rate of fermentation, decreased the time required to complete fermentation at all dissolved-solid concentrations, and stimulated the production of s lightly more ethanol than was produced by the corresponding unsuppleme nted control mashes. The optimum temperature for maximum ethanol produ ction in urea-supplemented very-high-gravity,wheat mash was 27 degrees C. These data are important for the industrial assessment of very-hig h-gravity fermentation technology.