Extension, Cooperative
Date of this Version
1986
Document Type
Article
Abstract
In the conventional production of alcohol from grain for fuel, byproducts are produced with excellent feeding value for ruminants. Appropriate use of these byproducts aids the efficient production of animals and enhances the economics of alcohol production. In the fermentation of corn to produce alcohol, the starch in the corn is converted to alcohol and carbon dioxide. The nutrients in the corn other than starch are concentrated about three times because corn is about two-thirds starch. Even though starch is high in energy, the one-third of the corn remaining in the byproduct after fermentation contains as much energy per pound as did the corn from which it was produced. Two-thirds of the total weight of the corn is lost but the concentration of energy in corn and distillers byproducts is similar. This energy is mainly in the form of protein, fiber and fat. Two byproducts are produced: distillers grains and thin stillage. Characteristics of the nutrients in the two byproducts are quite different and often confuse the discussion of distillers byproducts. After fermentation of the corn by yeast to produce alcohol and then distillation to recover the alcohol, the remaining material is called whole stillage. In most cases, whole stillage, which is usually 90 percent water, is screened or centrifuged to produce distillers grains and thin stillage. The distillers grains contain primarily unfermented corn residues (protein, fiber, fat). The thin stillage contains yeast cells, soluble nutrients and very small corn particles. Thin stillage is often called distillers solubles. However, this is a misnomer, because much of the material is not really soluble, but is instead a suspension of fine particles.
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© 1986, The Board of Regents of the University of Nebraska on behalf of the University of Nebraska–Lincoln Extension. All rights reserved.