Our Industry: Grains - Corn

CORN

What It Is, How It's Marketed and How It's Used

Corn has been an important part of human civilization.

It generally is believed that corn evolved from a wild grass that grew about 60,000 years ago. Corn formed the background of tribal civilizations in the Western Hemisphere. The Mayan, Aztec and Inca civilizations all depended on corn for food and as an important part of their religion and art.

After Christopher Columbus discovered corn in the Western Hemisphere, he introduced it to Europe where it was grown for many years only out of curiosity. In North America, the Indians, as well as the colonists, relied on corn for survival.

Now, corn is grown in nearly all temperate and tropical regions of the world. The United States is the leader in corn production, normally growing 35 to 50 percent of the entire world crop. Corn also is by far the most common kind of grain grown in the United States, normally accounting for almost two-thirds of total U.S. production of all grains.

There are three basic types of corn grown in the United States:

1. Dent Corn accounts for about 99 percent of all U.S. corn production. It's called "dent" corn because of the indentation on the top part of the kernel, which is caused by a shrinkage of starch. There are three different classes of dent corn grown in the United States:

• Yellow, which accounts for most of the dent corn, is used for livestock feed and for wet milling into sweeteners, starches and other products for human and industrial use.

• White, which is used by dry corn millers to manufacture corn flour, hominy and grits, and for industrial uses.

• Mixed, which is used for livestock feed.

2. Sweet Corn accounts for only about 1 percent of the total U.S. corn acres. This is the kind of corn you buy in the grocery store in cans or as "corn-on-the-cob."

3. Popcorn accounts for less than 1/2 percent of total U.S. corn acreage.

4. Flint Corn (which more commonly is grown in Argentina and South Africa, and which has a hard, or flinty, starchy layer covering the soft starch in the center of the kernel.

The Corn Plant -- Stages of Life

Corn is a warm-season crop. There are several stages in the growing process:

• Planting: Corn planting occurs from early April through late May, depending on the region of the country. One to three weeks after planting, the plant emerges from the soil surface.

• Pollination: About midway through the growing season -- in July -- the plant reaches its maximum height and pollen is shed from the tassels to fertilize one or two ears on each plant.
  
  
• Growing: Seven to eight weeks after pollination, the kernels grow. Kernels reach their maximum weight in September. After that, the plant begins to lose its green color and the kernels, stalks and leaves begin to dry.
  
  
• Harvest: Harvest usually starts in early October, once the kernels have dried (optimally to between 15 to 22 percent range). A special combine known as a "picker-sheller" is used, which removes the ear from the plant, removes the husks from the ear and shells the grain by removing the kernels from the cob. Most of the corn usually is harvested by mid November.

Corn -- Its Journey to Market

About one-third of the corn crop typically remains on the farm to be used as animal feed. The rest of the crop is sold by the farmer, usually to a country elevator located near the farm.

The country elevator also typical is where the farmer obtains the supplies -- such as seed, fertilizer and chemicals -- needed to grow the crop. Once the crop is harvested, the country elevator dries, stores and conditions the grain. Country elevators range in size from 50,000 bushels to several million bushels of storage capacity.

The country elevator then sells the corn. The buyer may a local livestock feeder. Or it may be a feed mill, a dry corn miller, or a wet corn miller. Or it may be a terminal elevator -- a large grain handling facility located in such major marketing areas as Kansas City, Minneapolis, Portland, St. Louis and Toledo -- which stores and conditions grain before selling and shipping it to an export elevator, miller or processor. Or the buyer may be an export elevator that intends to sell the grain to an overseas consumer.

When entering into a contract for corn, the buyer and seller agree on the price, quantity and quality of grain to be delivered; the price discounts or premiums that will apply if the actual grain shipped is of a higher or lower quality than requested; and how the grain is to be shipped (by rail, barge or truck).

As corn is traded in the marketing system, whoever owns it faces market risk as prices rise and fall to reflect supply and demand. For this reason, corn is often "hedged" in the futures market. In "hedging," a person buys or sells an equivalent quantity of grain at a future month at a set price. That protects the buyer from unexpected price changes that can trim an already small profit margin.

Corn -- How It's Transformed into Useful Products

Corn is found in countless consumer and industrial products. But first, it must be processed by:

• Feed millers, who grind the whole kernel and mix it with different kinds of vitamins, tract minerals, salt, molasses and other ingredients to make wholesome feed for livestock and poultry. The corn and grain byproducts account for 85 to 95 percent of the feed ration; or
  
  
• Wet corn millers, who soak corn in a solution of warm water and sulfur dioxide in a process known as "steeping." The softened kernels then are pulped in mills and the kernel is separated into its various parts -- hulls, germ, gluten and starch; or
  
  
• Dry corn millers, who clean and then temper the corn with hot water and steam for two to six hours to soften the bran and germ so they can be separated from the endosperm. Sifting machines separate the flinty, coarse, granular material. Then the miller extracts corn oil, flaking grits and corn flour from the kernel.

Many Good Things Come from Corn

Whole kernel: Ground and mixed with ingredients and vitamins to make animal feed. Animals fed corn produce:

• hamburgers
• eggs
• ice cream
• hot dogs
• milk
• pork chops
• chicken
• cheese
• bacon
• turkey

Hull: Fibrous layer covering the kernel. Produces corn gluten feed and meal.

Germ: Elongated oval portion. Contains polyunsaturate corn oil and protein. Used in:

• cooking oils
• margarine
• mayonnaise
• salad dressings
• shortening
• soap
  

Gluten: Sides of the kernel contains most of the protein. Used in animal feeds, particularly poultry feed (fives golden color to egg yolks and skin color of chickens.)

Starch: Fine white powder. Can be heated under pressure to produce corn syrup. Used in:

• baking soda
• soft drinks
• chewing gum
• baby foods
• ice cream
• jellies and jam
• processed cheeses
• medicine
• fuel ethanol
• paper
• glue

Why Is Corn on the Cob Sweet and How Does Popcorn Pop?

You may have wondered why corn-on-the cob tastes sweet and how popcorn pops. Well, here are the answers:

• Sweet corn tastes that way because it is bred with a genetic deficiency that prevents the kernels from converting sugars into starch. The sugars then accumulate in the kernels.
  
  
• Popcorn kernels have a very hard middle (the starchy part that is known as the endosperm) -- that is much harder than dent corn or sweet corn. When the popcorn kernels are heated, steam pressure builds inside the kernel and it pops.
  
  

Click here to view map of "Corn Growing Areas"