Starch is a biopolymer, defined as a homopolymer, consisting of only one monomer, D-glucose (Pongsawatmanit et al., 2007). To produce bioethanol from starch, it is necessary to break down by hydrolysis the chains of this carbohydrate to glucose syrup or fermentable sugar that can be converted into bioethanol by yeasts (Balat et al., 2008). This type of feedstock, mainly corn and wheat, is the most utilised for bioethanol production. The starch-based bioethanol industry has been commercially viable for about 30 years (Barretts de Menezes, 1982). In that time, tremendous improvements have been made in enzyme efficiency, reducing process costs and time and increasing bioethanol yields (Kim and Dale, 2004). However, there are two main reasons for the present high cost: on the one hand, the usual yeast S. cerevisiae cannot utilise starchy materials, so large amounts of amylolytic enzymes, namely glucoamylase and a-amylase, need to be added (Apar and Ozbek, 2004); on the other hand, the starchy materials need to be cooked at a high temperature (413-453 K) to obtain a high bioethanol yield. In the last years, the possibility of hydrolysing starch at low temperatures (liquefaction) for achieving energy savings has been investigated (Shigechi et al., 2004; Mojovic et al., 2006; Robertson et al., 2006).