Watch clips from Discovery Channel's Moonshiners
Watch clips from Discovery Channel's Moonshiners

Ethanol production is entrenched in American history. Revenue agents in West Virginia examine the boiler of a still used to manufacture illegal moonshine alcohol.

Evans/Three Lions/Getty Images

Introduction to Can I make my own ethanol?

Muffled laughter behind closed doors, flapper girls dancing, the clink of glasses, guys in fedoras with Tommy guns sipping illicit gin: All of these are sights and sounds of the prohibition era. In the 1920s, alcohol was illegal and expensive to get in the United States. Hidden moonshine stills popped up around the country, feeding unfiltered and sometimes dangerous alcohol to a thirsty crowd. These days, moonshine stills can do more than help circumvent prohibition laws. They can help us out of our current fuel crisis by letting people make their own ethanol.

Lots of people make a fuss about how ethanol costs more per gallon and is less efficient to produce than gasoline. One thing is certain: Ethanol production does have a lot of variables -- everything from the feedstock (bio-material required to make ethanol fuel), all the way to the equipment used to distill it. One way you can control both of these variables, however, is to make your own ethanol.

Why would you want to do that when you can just drive down the street and fill your tank with E85 from the pump? Plenty of people around the United States want to control where their energy comes from and know exactly what they are putting in their tanks. Certain U.S. regions don't even offer ethanol as an option, claiming that there's no market for it.

Making your own ethanol can be fun, cost-effective and better for the environment. Your engine will run cleaner and there will be a reduction in the amount of toxic emissions that burning gasoline produces. It's a relatively simple process: All you need is some form of feedstock, a way to ferment it and a way to distill it. Basically that's it. Of course, there's also a certain level of danger involved in producing your own ethanol and we'll look at that, too.

On the next page, find out some of the best materials for making fuel.

Packaged seed corn sits in the barn of a seed dealer and farmer. This year in the United States, more acres of corn are expected to be planted than any year since World War II to help meet increased demand, driven in part by increased ethanol production.

Scott Olson/Getty Images

Ethanol Feedstocks

Ethanol is a fuel made from the fermentation and distillation of sugars and starches. In short, it means running your car on alcohol. Feedstocks are the basic components of ethanol. Just as different foods give your body more or less energy, so will different stock plants make for better ethanol. Everybody's heard about making ethanol from corn. Corn, however, doesn't put out nearly the yield of energy that sugar does. Sugar cane isn't a common crop in the United States, so that particular feedstock could actually make our situation worse if we tried to use it. Just imagine the gas we'd use just to ship the cane! The key to making great ethanol is to find feedstock close to you and make it work.

While there is plenty of corn in the Midwest, the Southeast and Northwest are better known for logging industries. Ethanol distilleries in these states use leftover wood chips and tree parts to produce ethanol. If you live on a farm, you can use leftover straw, husks and grain. If you can manage this, not only are you recycling your waste into something useful, you're cutting down on a chunk of your overall fuel costs. Your feedstock is free!

If you don't have this sort of useful waste available and need to grow your own feedstock, do a little research before running off to buy corn. There are plenty of crops that grow well in different regions and make for better fuel. For example, one acre of corn can be processed into about 330 gallons of ethanol, while one acre of switchgrass can be processed into about 1,150 gallons of ethanol a year! [source: Bioenergy]

Now that you've got your feedstock, you'll need to ferment it. Fermentation is a simple process:

sugary/starchy foods + yeast = alcohol and CO2

sugary/starchy foods + yeast = alcohol and CO2

The yeast is living bacteria that eat the sugar or starch and excrete alcohol and carbon dioxide in the fermentation process. Think of that the next time you drink a beer!

Once your ethanol has fermented, you will have a mixture that is a combination of ethanol and its byproduct, water. Since you can't burn water in an engine, you will need to remove it through a process called distillation.

Want to know how to separate ethanol from water? Read the next page to find out.

Distillation is really the same process, whether you're working with large or small quantities.

Marcus Brooke/Getty Images

Ethanol Distillation

Distillation means taking the fermented ethanol and water mixture and adding heat to separate them -- typically in a still. Since ethanol evaporates faster than water, the ethanol rises through a tube, collects and condenses into another container. The water is left behind.

There are a lot of different kinds of stills, including pot stills, vacuum stills, reflux stills and solar stills, which differ in setup and the way you heat your product. The two most widely used in-home ethanol production units are solar stills and reflux stills. Designs for all of these can be found online, and there are as many different variations for all of them as human innovation will allow. If you have any doubts about the safety or credibility of a particular still, do not attempt to use that design.

One of the simplest and most Earth-friendly distilleries is a solar still. As its name implies, a solar still uses the sun's energy to heat and separate the product. This is the most Earth-friendly design because it doesn't use any other type of fuel, such as wood for a flame or coal for electricity, to make your fuel. The downside to this still design is that it can be inconsistent. It depends entirely on how much sun you get around your house -- and it also makes fairly weak ethanol.

Reflux stills are the most common and efficient stills used to make ethanol at home. Reflux stills usually use electricity or natural gas for heating. In the past, reflux stills used several increasingly smaller boiling pots to separate ethanol from water into increasingly concentrated forms. Now, reflux stills use one boiling pot and a complex reflux column which is broken down into smaller spaces to imitate other boiling pots. It takes up less space and provides for a more pure product.

Prior to distilling ethanol, you'll need to have a permit. Keep reading to find out how to get one.

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The MicroFueler allows consumers to create ethanol using only sugar, yeast and water.

Courtesy of E-Fuel Corporation

Ethanol Production Costs

The costs associated with home ethanol production have so many factors involved that concrete numbers are impossible. Here's a guide to the steps of making ethanol so that you can make the calculations yourself:

  • Feedstock: If you're using waste material such as sawdust or grain, this is free. If you're growing feedstock, you need to calculate the price of seeds as well as the time and energy it takes to grow and harvest the crop. For example, switchgrass takes much less time and water to grow than corn.
  • Equipment: A solar ethanol still can usually be made with simple materials often found around the house. Building a boiler and a reflux column can cost anywhere from $30 in blueprints and about $50 in materials, to around $200+ for a fully-built reflux still on eBay. If you really want to make it easy on yourself, you can buy an EFuel100 MicroFueler for about ten thousand dollars.
  • Gasoline: You need to factor in the price per gallon of gasoline. You'll be required to mix this with your ethanol. For example, if you're making E95 (95 percent ethanol, five percent gasoline) with gasoline that is priced at $4 per gallon, you'll be mixing 20 cents worth of gasoline into each gallon of ethanol you produce.
  • Output: The more ethanol­ you get out of your still and the more efficient you become at distilling, the more your costs will go down.­

The government likes to know when and where people are brewing ethanol. To be able to legally distill, in the United States you need to file a permit with The Alcohol and Tobacco Tax and Trade Bureau (TTB). The permit is free. The application is five pages long and takes about a month to process. Authorities can stop by at any time to inspect your still and make sure that you're not drinking the product. While you can make 100 percent ethanol (E100) to run in your vehicle, the best way to assure the authorities that your homemade ethanol is used for fuel is to create a mix of about 4 to 6 percent gasoline per gallon of ethanol.

Ethanol is actually pretty safe to make--some say it's even safer than going to a gas station. If your still is made correctly, everything should be self-contained and well-regulated. That being said, there is always Murphy's Law.­ The best way to stay safe is to remember that the point of ethanol in a combustion engine is to explode -- you should respect that. Following safety instructions is important. Pay special attention when installing vents, timers and over-boil regulators. Most importantly, never smoke near your ethanol still.

Any gasoline engine can run on small amounts of ethanol. If you're going to use large quantities of ethanol (like E85), your vehicle will require an E85 conversion kit. You can buy these kits online from several retailers. They cost anywhere from $100 to $1,000 depending on the technology and how comfortable you are installing them yourself.

The yellow fuel cap on this 2007 Chevrolet Impala lets consumers know they can fill the tank with gasoline or E85.

Chip Somodevilla/Getty Images

Some vehicles, called flex-fuel vehicles, can run on ethanol already. In fact, millions of cars on the road can run on ethanol, and their owner's don't even know it. To find out if your vehicle is flex-fuel compatible, check your owner's manual or the inside of your fuel filler door for an ID sticker or some other indication that your vehicle is E85 compatible.

Small engines like lawnmowers, hedge trimmers and chainsaws don't need to convert anything to operate on ethanol; however, you may notice a smaller energy output. Some people find ways to get more output by playing with choke valves and fuel additives.

Making your own fuel can have a lot of advantages. These can include tax credits and HOV lane access -- you must display alternative-fuel plates -- to the satisfaction of knowing where your fuel came from. You should always follow the safety instructions, but don't forget to be creative and find ways to incorporate ethanol into more than just your car.

If you want to learn more about making your own ethanol, then follow the links on the next page.

Lots More Information

Related HowStuffWorks ArticlesMore Great LinksSources
  • AAMCO. Eco-Green Business. http://www.aamco.com/ecogreen/e85FleetConv.html
  • Alcohol and Tobacco Tax and Trade Bureau (TTB) - U.S. Department of the Treasury. May 2007. http://www.ttb.gov/forms/f511074.pdf
  • Bioenergy Feedstock Information Network. "Biofuels from Switchgrass: Greener Energy Pastures." http://bioenergy.ornl.gov/papers/misc/switgrs.html
  • Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) Online. http://www.atf.treas.gov/
  • Flex Fuel US. "Alternative Fuel Incentives." http://flexfuelus.com/ALTERNATIVE-FUEL-INCENTIVES
  • Fuel Economy. "Flex-fuel Vehicles." http://www.fueleconomy.gov/feg/flextech.shtml
  • Internal Revenue Service (IRS). "Certain Fuel Mixtures and the Alternative Fuel Credit." March 2008. http://www.irs.gov/pub/irs-pdf/f8849s3.pdf
  • Popular Mechanics. "Micro Fueler Is First Ethanol Kit for Brewing Backyard Biofuels on the Cheap." 05/08/2008. http://www.popularmechanics.com/blogs/science_news/4262690.html