Once harvest season is over and combines have made their way through the cornfields, the crop begins its journey to its final destination. Corn, one of the most versatile crops on the planet, ends up in a multitude of everyday products including crayons, baby food and pancake mix, as well as industrial items like insecticides and detergents.
Because of its versatility, corn is a popular cash crop for farmers across the country. According to the United States Department of Agriculture, the U.S. produces about 14 to 15 billion bushels of corn each year. The state of Iowa is responsible for producing an average of over 2 billion bushels of corn annually.
Rebecca Vittetoe, a field agronomist for Iowa State University Extension and Outreach, explained that the most common type of corn grown in the state is the #2 yellow dent corn.
“Its versatility as a product helps increase demand for it. In most of the Midwest, the most commonly grown corn will be the #2 dent,” Vittetoe said. Inside a kernel of corn is starch, fiber, protein and oil, all of which gets utilized in different products, Vittetoe pointed out.
The field agronomist noted that there are many misconceptions about what types of corn farmers usually grow.
“Lots of people, the first thing they think of is sweet corn, but that’s less than 1 percent of the corn we grow here in Iowa,” Vittetoe explained, noting that most people only think of corn as a product consumed by humans.
“If you try to eat No. 2 dent corn, it would taste awful. It would be hard to chew, you could potentially break a tooth,” Vittetoe said.
The field agronomist noted that most farmers will either put their corn into storage or sell immediately to buyers or co-ops.
Doug Seyb, a corn farmer in Donnellson, sells most of his crop in January, with most of his crop sold by the end of July to avoid getting too close to the next harvest season.
With an especially wet spring this past year, Seyb explained that the current year’s harvest had to be dried because of high levels of moisture.
“The last time we had to dry corn was in 2014. To store it, if the moisture is at 15 percent, it will begin to spoil. This year, a lot of the corn came out of the field over 20 percent,” Seyb said.
Like many other corn farmers, Seyb sells his crop to a multitude of buyers, including fertilizer manufacturers as well as companies that make corn sweeteners and livestock feed.
While corn ends up in a variety of products, about a third of the corn produced in the country gets processed and turned into ethanol, a renewable fuel.
Tim Leiting, the chief operating officer of Big River Resources, LLC, an ethanol production company whose first plant was started in West Burlington, noted that of the approximately 15 billion bushels of corn produced in the country, about 5 billion gets processed into ethanol. The West Burlington plant purchases about 40 million bushels a year to make their products while the company overall processes about 150 million bushels of corn per year.
Leiting explained that at the plant, corn gets ground up which “opens up the starch” in order to be able to ferment the crop into alcohol.
“About 72 percent of a corn kernel is starch. Then you also have about 4.2 percent of corn oil in a kernel of corn and the remainder is protein. Our dried distillers grain is a combination of the fiber and the protein,” Leiting said. Those products are separated out after the corn is processed.
“[The ground corn is] put into a mash with water and enzymes and other chemicals … the enzymes break the starch down to simple sugars so the yeast can ferment it, no different from making beer,” Leiting explained.
“From there, once all the starch is processed, we take all the solids out. The liquid portion of the mash, we distill it, which separates the alcohol from the water and produces 200 proof ethanol,” he continued.
From one bushel of corn (equivalent to 56 lbs.), the plant will produce 2.9 gallons of fuel grade ethanol, 15 lbs. of dried distillers grain and .7 lbs. of corn oil. The chief operating officer estimates that the entire process takes about 65 hours.
Once the ethanol leaves the plant, it gets blended in gasoline and adds octane to fuel, providing oxygen so that the gasoline burns cleaner.
“It reduces tailpipe emissions because you get more oxygen for better combustion in your engine,” Leiting said.
“You can make ethanol out of anything that is starch. You can make it out of sugar beets, milo, you could use wheat … [corn] is easiest. There’s a lot of it, it’s price-competitive, it’s easy to handle, it’s easy to store and so it’s cost effective,” the chief operating officer said of why corn is used to make ethanol.
“Corn, if you look on a worldwide basis, is a huge crop. It’s the biggest crop of any grain out there and the reason for that is because it has so many uses. Pretty much every country uses corn or if they have the climate, they grow corn. It’s a very versatile grain. Corn is almost a currency, it gets shipped across the world,” Leiting said.