There are two main sources of these grains. The traditional sources were from brewers. More recently, ethanol plants are a growing source. It is created in distilleries by drying mash, and is subsequently sold for a variety of purposes, usually as fodder for livestock (especially ruminants).
In beer or whiskey production grains such as corn are ground to a coarse consistency and added to hot water. After cooling, yeast is added and the mixture ferments for several days to a week. The solids remaining after fermentation are the distillers grains.
Fuel production
One 56 pound bushel of corn produces 18 pounds (2.72 gallons) of ethanol and approximately 17 pounds of distillers grains in various forms:[1]
