Starch is relatively cheap and easy to convert into ethanol, so parts such as grain that are high in starch are the parts that are currently being used. Parts such as stalks and cobs are low in starch but high in cellulose and hemicellulose. The technology to convert cellulose into ethanol is currently only in the pilot or demonstration stage, and commercial feasibility is still unknown. If the cellulosic conversion technology becomes commercially feasible, future expansion of biofuel production is likely to utilize the whole corn plant (or other dedicated energy crops). However, current ethanol processing plants are likely to continue to operate and use corn grain as the feedstock for some years to come. For more information see Biomass Feedstocks and Energy Independence and Feedstocks for Biofuel Production. Contributor: Bill Lazarus, University of Minnesota