Distillers grains are a

cereal A cereal is a grass cultivated for its edible grain. Cereals are the world's largest crops, and are therefore staple foods. They include rice, wheat, rye, oats, barley, millet, and maize ( Corn). Edible grains from other plant families, ...

byproduct A by-product or byproduct is a secondary product derived from a production process, manufacturing process or chemical reaction; it is not the primary product or service being produced. A by-product can be useful and marketable or it can be cons ...

of the

distillation Distillation, also classical distillation, is the process of separating the component substances of a liquid mixture of two or more chemically discrete substances; the separation process is realized by way of the selective boiling of the mixt ...

process. Brewer's spent grain usually refers to

barley Barley (), a member of the grass family, is a major cereal grain grown in temperate climates globally. It was one of the first cultivated grains; it was domesticated in the Fertile Crescent around 9000 BC, giving it nonshattering spikele ...

produced as a byproduct of brewing, while distillers grains are a mix of wheat, maize, rice and other grains. There are two main sources of these grains. The traditional sources were from brewers. More recently,

ethanol Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the ps ...

biofuel plants are a growing source. It is created in

distilleries Distillation, also classical distillation, is the process of separating the component substances of a liquid mixture of two or more chemically discrete substances; the separation process is realized by way of the selective boiling of the mixt ...

by drying mash, and is subsequently sold for a variety of purposes, usually as

fodder Fodder (), also called provender (), is any agriculture, agricultural foodstuff used specifically to feed domesticated livestock, such as cattle, domestic rabbit, rabbits, sheep, horses, chickens and pigs. "Fodder" refers particularly to food ...

for

livestock Livestock are the Domestication, domesticated animals that are raised in an Agriculture, agricultural setting to provide labour and produce diversified products for consumption such as meat, Egg as food, eggs, milk, fur, leather, and wool. The t ...

(especially

ruminants Ruminants are herbivorous grazing or browsing artiodactyls belonging to the suborder Ruminantia that are able to acquire nutrients from plant-based food by Enteric fermentation, fermenting it in a specialized stomach prior to digestion, principa ...

Maize Maize (; ''Zea mays''), also known as corn in North American English, is a tall stout grass that produces cereal grain. It was domesticated by indigenous peoples in southern Mexico about 9,000 years ago from wild teosinte. Native American ...

-based distillers grains from the ethanol industry are commonly sold as a high protein livestock feed that increases efficiency and lowers the risk of subacute acidosis in beef cattle. Recently, studies indicate that dried distillers grains with solubles (DDGS) as a food source for human consumption may have some benefit in reducing heart disease risk. The mash left over from the process contains nutrients, such as protein, fiber, germ, vitamins, and minerals, and research suggests that the flour made from DDG will work well with cookies and flatbread. The texture and taste of food-grade DDG, especially maize, has been compared to breakfast cereal.

Wet and dry distillers grains

There are two common types of distillers grains: * Wet distillers grains (WDG) contain primarily unfermented grain residues (protein, fibre, fat and up to 70% moisture). WDG has a shelf life of four to five days. Due to the water content, WDG transport is usually economically viable within 200 km of the ethanol production facility. * Dried distillers grains with solubles (DDGS) is WDG that has been dried with the concentrated thin stillage to 10–12% moisture. DDGS have an almost indefinite shelf life and may be shipped to any market regardless of its proximity to an ethanol plant. Drying is costly, as it requires further energy input. In the US, it is packaged and traded as a commodity product.

Production

In beer or whiskey production, grains of corn (including wheat and maize), are put through a

mashing In brewing and distilling, mashing is the process of combining ground grain – malted barley and sometimes supplementary grains such as corn, sorghum, rye, or wheat (known as the " grain bill") – with water and then heating the mixture. Ma ...

process, where grain is ground and added to hot water. The starch in the grains undergoes saccharification by enzymes, turning the starch into sugars that are released into the water. The water is removed from the grain, and becomes

wort Wort () is the liquid extracted from the mashing process during the brewing of beer or whisky. Wort contains the sugars, the most important being maltose and maltotriose, that will be Ethanol fermentation, fermented by the brewing yeast to prod ...

for brewing. The remaining grain, called "spent grain" for the removal of simple sugars and starch, can then be sold as a by-product. The conversion rate of grains to ethanol and distillers grains varies with the different types of grains and the process used. The details are outlined below: * The conversion rate of maize to distillers grains is: One

tonne The tonne ( or ; symbol: t) is a unit of mass equal to 1,000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton in the United States to distinguish it from the non-metric units of the s ...

of maize produces 378 L of ethanol and 479 kg WDG (70% moisture content), or 309 kg of DDGS (10% moisture content). * The conversion rate of wheat to distillers grains is: One tonne of wheat produces 372 L of ethanol and 457 kg WDG (70% moisture content), or 295 kg of DDGS (10% moisture content).

References

External links

Information page from the University of Minnesota

Ethanol Producer MagazineIowa Corn
Distilled drinks Fodder By-products {{Agri-stub

Wet and dry distillers grains

Production

See also

References

External links