Because of the recent increase in the gas price and interest in environmental issues, the demand of ethanol
as substitute of gasoline is rapidly increasing. Basically, 5 steps are included in ethanol production
composed of grinding, cooking, fermentation, distillation, and hydration. In each step, there are several
ideas to improve its productivity and benefitablity. In this paper, I put some explanation about industrial
choice or idea. Also, many new studies are going on such as lignocellulosic biomass, immobilization cell
system. While these new studies are very efficient, they are not mature to be utilized for industrial purpose.
Also, bioethanol as energy source has some unclear aspects from the stand points of sustainable energy and
its environmental stress. In this sense, still, there are so many concerns to clear to make bioethnaol a real
ideal energy source.