As the starch is a polymer exclusively composed of glucose residues, it has become a very important feedstock for ethanol production. For this, the breakdown of starch into glucose with the subsequent conversion of glucose into ethanol using appropriate fermenting microorganisms is required. The technologies for starch hydrolysis will be discussed in Chapter 5. The grains are the feedstock most used for ethanol production from starchy materials, especially corn and wheat, though bioethanol production from rye, barley, triticale (Wang et al., 1997), and sorghum (Zhan et al., 2003) has been reported. Besides the grains, some tubers, such as the cassava and potatoes, offer significant starch contents. In a similar way, etha­nol from sweet potatoes, eddoes, yam (Hosein and Mellowes, 1989; Nigam and Singh, 1995), plantain, and bore (Aya et al., 2005) has been produced.