The Walking Dead: How they are making fuel from corn

Andrew Lincoln as Rick Grimes, Norman Reedus as Daryl Dixon - The Walking Dead _ Season 9, Episode 4 - Photo Credit: Gene Page/AMC
Andrew Lincoln as Rick Grimes, Norman Reedus as Daryl Dixon - The Walking Dead _ Season 9, Episode 4 - Photo Credit: Gene Page/AMC /

Wondering how Daryl still has fuel for his bike when everyone else is riding horses? They’re making ethanol. Here’s how they do it.

There are a lot of people wondering how in The Walking Dead world Daryl’s still got fuel for his motorcycle and how there is fuel for farm equipment when by this time in the apocalypse everyone else is riding horses for transportation because there is no more viable gas. It’s one of the plot points that is brought up often by people decrying the show’s authenticity. But it’s very possible, in fact it would be fairly easy, for the survivors to make ethanol.

The Sanctuary survivors are not faring too well since Negan was captured. In the 18 months that have gone by since the end of All Out War they have been trying to grow their own crops and feed their own people but nothing is growing very well at The Sanctuary. While it’s possible to have some container gardening there the site isn’t really situated well to grow crops in the amount that would be needed to feed everyone left at The Sanctuary. It’s a factory site with concrete and asphalt, not the rich soil fields that Hilltop sits on. So The Sanctuary is struggling.

Maggie mentions that The Sanctuary has been paying for food and supplies from The Hilltop with ethanol. Ethanol is a biofuel that can be made from crops like sugar beets and corn, and it can be made from switchgrass which is native to Virginia.

Since the communities are relying mostly on horsepower and their own feet to get around and to do the farm work it’s not unrealistic at all that a large factory site like The Sanctuary would be able to make enough ethanol to keep Daryl’s bike and some of the farm equipment running. They also probably have several cars and trucks ready and fueled in case they need escape vehicles. Here’s how The Sanctuary can make ethanol from their dead corn crops:

Making Ethanol

There are two different methods for making ethanol: dry milling and wet milling. The survivors at The Sanctuary would probably be using the dry milling method because they would have the equipment on hand to fine chop the dead corn and wheat that they were trying to grow. The entire stalk of the corn as well as any other remaining plant material would need to be ground up or chopped up and then placed in a pot or tub and heated to about 100 degree. This will break down the starch in the corn and wheat and convert it to sugar.

Once the corn and other materials have been broken down they would need to be placed in a barrel or container of some kind with hot water and stirred up. Once the mixture is stirred and is at about 90 degrees yeast is added and stirred into the mixture. The barrel or container would need to be covered loosely and then maintained at a constant temperature of about 70 degrees so that the mixture inside would ferment. That process usually takes 5-7 days. After that time the live yeast would get filtered out and the mixture would go through a distillation process.

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A still would be needed in order to get the ethanol out of the fermented mixture but it would be easy enough for Eugene to build a still or for the survivors to find out. After being distilled the mixture needs to be filtered and then it will be usable as fuel.

Doesn’t Ethanol Need To Be Mixed With Gas?

Yes and no. Most of the time ethanol is mixed with gasoline in various ratios so that it can be used as fuel in most cars and trucks. Most often gasoline is mixed with 10% ethanol. But there are different grades of fuel that higher ratios of ethanol to gas, including E85 which is 85% ethanol and 15% gasoline. While it’s not used in the US there is a mixture that is 95% ethanol. And engines can run on pure ethanol, although that would damage the engine over time and the vehicle might not start during cold weather.

So while pure ethanol is not an ideal fuel it is a viable option for the survivors to use since they have an abundance of corn and other materials that are necessary to make it. And with someone like Eugene around to build the stills and other supplies they would need and a factory set up like The Sanctuary to make it there would be enough to at least power the farm equipment, Daryl’s bike, and possibly the power generators.