The following quick review of the chemical manufacturing processes involved in alcohol production is excerpted from Chapter 3 of Fuel from Farms , which is available from the National Technical Information Service.
Corn is used as the feedstock example.
While molasses is currently the predominate ethanol feedstock in Louisiana, corn and milo are expected to dominate any expansion. Basically, fermentation is a process in which microorganisms such as yeasts convert simple sugars to ethanol and carbon dioxide. Later steps break down the individual cell walls of the starch. The choice of enzymes will determine the supervision the cooking stage will require. This breaks the cell walls of the starch.