It was found that both the growth of yeast cells and the formation of flavor components were accelerated by the presence of active carbon particles in the alcohol fermentation:of enzyme-saccharified solution. The factors governing the accelerative effect of active carbon were studied in the static fermentation. The profiles of concentration of dissolved oxygen (DO), dissolved carbon dioxide (DCO2), and yeast cells were measured along the vertical direction of themoromi (mash) during the

more »

... tion. The amount of increased DO derived from the active carbon added was relatively low, and little difference between the rates of DO consumption in the presence and absence of active carbon was observed. This suggested that the increasing DO had no significant effect on the growth of yeast cells in this study. In the presence of active carbon, DCO2 concentrations were clearly kept lower throughout the moromi in spite of a larger amount of CO2 evolved compared with that in the absence of active carbon. A good dispersiveness of yeast cells along the vertical direction of the moromi was observed in the active carbon-added moromi. The amount of iso-amyl acetate formed per total number of yeast cells was increased 2. 5-fold by the presence of active carbon. These results confirmed that DCO2 was a key factor governing the acceleration of the growth of yeast cells and the formation of iso-amyl acetate in the active carbon-added moromi.