Ethanol Quick Facts

Many of us know that ethanol exists. It comes from corn and can be used to power our vehicles. But many people are afraid to use it for fear of hurting their car, truck, or SUV. Today, let’s talk more about what ethanol is, where it comes from, and who can use it.

In chemistry terms, ethanol is ethyl alcohol, or C2H60. It can be made from many different things, including sugar cane, cassava, and sorghum. Essentially what happens is the sugars in the grain are fermented and turned into alcohol.

It’s not an incredibly new idea, either. In fact, there was even an episode of Dukes of Hazzard about it in 1979 (High Octane, for the fans out there). Bo and Luke entered a contest to find a cleaner burning fuel and entered their homemade moonshine (essentially just food-grade ethanol) in the contest. Of course, they had to fool Boss Hogg and Rosco P. Coltrane in the process, but in the end they won the prize money. Of course. They’re the Dukes.

Though the 1970s did mark the beginning of the modern ethanol industry, it didn’t all start then. According to the Energy Information Agency, ethanol was first used to power an engine as early as 1826! It was used as fuel for lighting in the 1850’s, too, but this use fell off when it was taxed as a liquor during the Civil War.

But anyway, how is ethanol made? Well, it really is just a bigger, fancier version of making moonshine. It works in the same way that other alcohol production works; yeasts break down sugars and create alcohol and carbon dioxide in the process.

Here in Iowa, we make ethanol from the starches of the corn kernel. Starches are essentially a long chain of sugar molecules. You may have heard of cellulosic ethanol, which yields the same product, but the process is a bit different, because the alcohol is created from cellulosic plant material, like corn stalks, instead of starches like in corn kernels.


First in the process to make ethanol, you have to physically break open the kernel so that the starches are exposed. Then, enzymes are introduced that break down that starch chain into a simple sugar. This is the same kind of thing that happens when you put a cracker on your tongue and don’t chew it. It breaks down anyway, because there are enzymes in your saliva that do the same thing. How cool is that?

Once the starches are broken down into sugars, yeast can be added. The yeast eats the sugar, and produces ethanol and carbon dioxide. After the yeast has done its job, the ethanol is purified, meaning any remaining water is removed using heat and molecular sieves. Lastly, ethanol is blended with a specific amount of gasoline to ensure that it cannot be used for human consumption.


In this graphic, you can see that there is a byproduct in ethanol production that creates animal feed. Depending on if it is dried or remains wet, it is either called DDGs (dried distillers grains) or “wet cake” (wet distillers grains). This is a common feed supplement because it is a high quality feed at a low price.

At the gas pump, however, there are a few common blends of ethanol to know about. The one that is the most common at gas stations is E-10. That means that the fuel is 10% ethanol and 90% gasoline. The second kind of fuel is E-15. E-15 is not at all gas stations, but is denoted with a blue handle at the pump. Many people stray away from E-15 for fear of hurting their engine, but that is a common misconception. All cars made in the year 2001 or after are approved to use E-15. E-15 options are generally cheaper (up to a dime per gallon), and burn cleaner than lower percentage ethanol blends.

Lastly, there is E-85, which is a remarkable 85% ethanol. This blend should only be used in Flex Fuel vehicles designed for that much ethanol. These vehicles are becoming more and more popular.


In summary, ethanol in Iowa is most commonly made from the starches in the corn kernel. The process yields a cleaner burning, cheaper, renewable fuel alternative, as well as a low cost and high quality livestock supplemental feed. Flex Fuel vehicles can use up to 85% ethanol (E-85) blends, and all cars built in 2001 or later can use E-15 blends.

To find a gas station with E-15, click here! For lessons relating to ethanol production, click here. And for a new book about modern corn production, click here.


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