Making Alcohol Fuel

Our bodies quickly make energy out of alcohol.  Our engines can do the same thing.  Of course, our engines will not go blind or die because of small amounts of contaminants in the batch, so we don’t need to be quite as careful as the big distilleries that make drinking alcohol.

The first fuel used in the internal combustion engine was alcohol.   Shortly after the internal combustion engine was invented petroleum distillation was discovered.  At that time gasoline was much cheaper to produce than alcohol, there was little concern over air pollution and oil supplies were thought to be inexhaustible.  Only a few foresighted people realized the disadvantage of using a fuel that had to be searched for and mined from underground.  Henry Ford was one of these.  He fought long and hard for the use of alcohol as fuel.


Making alcohol fuel is not far removed from chores farmers are used to.  What we are doing is growing a yeast crop for the alcohol it produces.  Grain is ground to make the starches more available.  Enzymes are then added to break the starch down to sugars.  These are the same types of enzymes that are found in saliva.  The sugar is then fed to yeast plants that digest the sugar and water and produce alcohol and carbon dioxide (along with more little yeast organisms.)  The yeast finally starves to death or kills itself off by overpopulation and too much alcohol.  We then remove the liquid, which is alcohol and water, and distill it.  The solids—the protein that was in the grain and the dead yeast organisms—are fed to animals as a protein supplement.


The substrate is the material from which the alcohol is made.  If you were just starting to farm, without any land or equipment, you would go out and look for land that would grow the crops you were interested in, and that you could afford.  Rich, black bottom-land will grow more than rocky, yellow hillsides.  Carbohydrates are what make an alcohol crop.  Sugar and starch are carbohydrates.  Crops with more carbohydrates will produce more alcohol per pound.  Table I-1 gives the amount of alcohol that can be produced from several different crops.

If you are buying the substrate, calculate the cost of the alcohol by dividing the cost per unit by the number of gallons that unit will produce.  For example, let’s say you want to produce alcohol from pure cane sugar and you can get that sugar at $12 per 100 pounds.  You can make 6.92 gallons of alcohol from that sugar so the cost would be $1.63 per gallon of alcohol.  If you were buying wheat at $4.50 a bushel and could make 2.56 gallons of alcohol from that wheat the substrate cost of the gallon of alcohol would be $1.75.

If you are growing the crop yourself, the more carbohydrates per acre, the more alcohol per acre would result.  If a crop will produce many gallons of alcohol per bushel, but will only produce a few bushels per acre, or if it has a very high production cost, it might be better to choose another substrate.  To figure the amount of alcohol per acre multiply the average production per acre by the amount of alcohol that crop can produce.  (Make sure the units are the same.)  In order to figure the cost of the substrate for each gallon of alcohol divide the cost of production per acre by the number of gallons that can be produced from the substrate grown on that acre.  For example, if you can grow 65 bushels per acre of wheat, which will produce 2.56 gallons of alcohol per bushel, the yield will be 166.4 gallons per acre.  At a production cost of $250 per acre, the substrate will cost $1.50 per gallon.

There are several things to consider when deciding what substrate to use.  In addition to expense, you should consider how dependable the crop is in your area, whether the equipment is available to plant, care for, and harvest the crop, whether you can store it until you are ready to use it and whether you have the equipment to prepare it.  Will you use the culls from your potato or fruit crops?  Will you plant what would once have been your set-aside acres into grain?  Will you use different crops at different times of the year?  Each operation is different and you must decide for yourself what is best.

There is a residue left over after the alcohol is made that is two to four times as rich in protein as the material going in.  Certain other nutrients are concentrated also.  With some substrates, this is a high-quality, high-protein animal food.  With others, it is not usable.  Could you formulate a supplement for your animals that would provide an amino acid balance?

Just as there is a need for water to make the nutrients in the soil available for plants, water must be available to dissolve the carbohydrates in the substrate you use.  The concentration of carbohydrates in the liquid should be between 10% and 25%.  The more water you add, the more complete the fermentation which results.  The less water, the more concentrated the alcohol in the brew.  The yeast will die when the concentration of the alcohol gets to be around 12%, so do not increase the sugar concentration above 25%.

The pieces of the substrate must be small enough that the enzymes and yeast can get to the carbohydrates.  Grain should be ground to the consistency of coarse cornmeal.  Other substrates should be ground, mashed or shredded as appropriate to the substrate.  Save all the juices. Sugar is water-soluble, and a lot of it can run off with the juice of some crops.  One-half of the water should be added to substrates containing starch, and they should be heated to soften the starch.  If you bring it to a boil for a short period of time, you will also kill unwanted bacteria and other microscopic weeds that would disrupt the production of alcohol.

Material  Unit             Lbs./Unit     % Fermentable   Gal./Unit
Wheat     Bushel            60 58.6 2.56
Corn or Milo  Bushel            56 57.8 2.34
Rye Bushel            56 54.0 2.19
Buckwheat   Bushel            48 57.2 1.99
Barley Bushel            48 54.3 1.89
Oats   Bushel            32 43.6 1.01
Sugar beets   Ton            2000 16.0 22.00
Sugar cane Ton            2000 11.0 15.18
Sweet potatoes Bushel            55 23.3 .93
Potatoes Bushel            60 15.6 .68
Jerusalem Artichokes Bushel            60 15.2 .59
Pure sugar     Bag            100 100.0 6.92
Corn sugar    Bag            100 100.0 6.00


Yeast makes alcohol from sugar.  Starches are long chains of sugar, and cellulose is a mass of starches cemented together.  Starches can be broken down using enzymes.  Enzymes make things happen that would not ordinarily happen.  Enzymes do not get used up in the reaction they make happen, although there are many things that will inactivate them.  A given enzyme will do only one thing.  It is like a key that will fit only one lock.  They act best at a certain temperature and pH.

Enzymes found in saliva, sprouted grain, and certain bacteria break the bonds that hold sugar together in starch chains.  These enzymes are called amylacea.  There are two different kinds of bonds between sugars in starch chains.  To break these bonds, it takes two different amylacea. They are glucoamylase and alpha-amylase.  The difference between the two is like the difference between right and left-hand scissors.  They approach from different directions and therefore are able to cut slightly different bonds.

There are enzymes called cellulases that break the sugars in cellulose apart.  These are produced by bacteria in the first stomach of ruminants and are very expensive to buy at this time. It would take about 30 to 50 cents worth of commercially available cellulase to produce a gallon of alcohol from cellulose-based materials

We use Diazyme, a glucoamylase and Taka-therm, an alpha-amylase.  Both are brand names from Miles Laboratory.  Taka-therm is most active at a pH range of 5.5 to 7.0, or in slightly acid to neutral conditions.  This can be measured with pH paper available at most drug stores.  It will retain its ability to act in a pH range of 5.0 to 11.0.  It works best at temperatures below 194E F.  If calcium ions are present in the water, it will act at higher temperatures, although higher temperatures for long periods of time still tend to inactivate the enzyme.  It should be stored at low temperatures (40° F).

Diazyme works best at a pH of 3.8 to 4.2 and at 140°F.  It will work in a pH range of 3.5 to 5.0. Temperatures above 176°F. will inactivate this enzyme.

When grain has been ground, mixed with cool water and heated you should add one ounce of Taka-therm per bushel.  The grain should be mixed with cool water at first to prevent balling but once it is moistened you may add water from some other step in the distillation process. This will save on energy for heating.  Do not add more than half the total water for the process.  The Taka-therm can be added any time after the heating process has begun.  The heat causes the starch to leave the grain and turn the mash to gel.  The Taka-therm liquefies this gel. As you heat, agitate the mixture so it will not scorch the grain and the heat will transfer faster.

After the Taka-therm has had at least half an hour to work, mix cooler water with the mash until it is about 140E F.  If you add all the water at this time and it is still not cool enough just let it set until it is.  Again, test the pH and adjust it to between 3.5 and 5.0. To lower the pH add any acid. Battery acid or muriatic acid is probably the most available.  To raise pH add lime.  It is unlikely that you will need to raise the pH before adding the Diazyme if you are careful as you add the acid.  Add ½ to 2 ounces of Diazyme per bushel and let it work at least half an hour. If you have not added all the water do that when the Diazyme has had a chance to work.  Let the mixture cool to 90°F.

If the enzymes are unavailable to you, making malt is probably the safest, easiest way to go, but even that takes time and attention.  Malt is simply sprouting grain.  Barley works best for malt, (produces more enzyme) although wheat is good too, and any grain will produce some enzyme. Malt should consist of 10 to 20% of the grain in the mash.

The first step in making malt is to soak the grain.  Pour fresh water over the grain until the water is six inches above the surface of the grain.  If this is done during the summer or in a warm room the water should be changed every four to six hours so the grain does not start to spoil or ferment.  It has soaked long enough when the grain can be crushed and leave no hard starch.

Next it should be germinated.  Germination takes place with the fewest problems if it is in a room about 55°F.  The soaked grain should be piled up to two feet deep.  Within 12 to 24 hours the grain will begin to produce heat.  This means it is beginning to grow.  When the center of the pile gets warm and wet, it should be turned.  This turning should take place every six to eight hours after the heating has started.  As the grain sprouts, it will have to be turned more and more often to keep the center of the pile around 65°F. The piles should also be spread out to become thinner and thinner until they are only a few inches deep.

Small rootlets will form first.  The sprouting should be stopped when these rootlets are about 2/3 the length of the grain.  If leaflets are allowed to form, they will use up a lot of starch that could otherwise be turned into alcohol.

It is very important that once the enzymes are formed the sprouting process be stopped quickly. Otherwise you will have a putrid mess.  To stop the process it should be used immediately, or dried with heat.  Start the drying process at around 95°F, then gradually warm it up to 160°F. When it is nearly dry and feels dry to the touch, you may raise the temperature higher to dry the malt completely.  It can get to 212°F at this point because the enzyme can only be inactivated at boiling temperatures if there is water present.

If you were making beer for drinking, you would then separate the dried rootlets, which are brittle and easily winnowed out.  Since you don’t care how the alcohol tastes, you can grind everything you have dried and mix it with your starchy substrate.  You now have beta-amylase, which will turn your starch to maltose, which the yeast can turn to glucose for use in making alcohol.  Do not heat the malted mixture above 170°F after water is added or you will inactivate the enzyme.


Brewer’s yeasts are in the air all around us.  Any natural fermentation is caused by one variety of yeast or another.  There are a variety of other living things—fungi, bacteria, viruses—floating around in the air, too.  High temperatures kill any living thing.  Therefore we have killed any natural yeast and other living organisms in the mash when we cooked it.  We must add yeast if we are to get any fermentation action.

Yeast companies have developed strains of yeast that ferment sugars swiftly and efficiently.  Therefore we can get the desired results more quickly than if we try to capture and breed our own.  The product called Brewer’s Yeast has materials added to retard the growth of other organisms in our brew as it makes alcohol.

Yeast will die at temperatures above 115°F.  Be sure you do not put the yeast in while the mixture is too hot.  They are most active near 90°F.  They are living things and produce heat by the action of living.  The fermentation vat will stay warm if it is insulated and inside a building but care must be taken to prevent it from overheating on hot summer days.  Dissolve the yeast in a small amount of water between 90°F. and 115°F. and mix it with your mash.  You should use two ounces of yeast per bushel of grain.

Yeast has two biological pathways.  If the yeast has oxygen it will reproduce and make large quantities of carbon dioxide.  If it does not have oxygen, it will produce alcohol and smaller quantities of carbon dioxide.  Therefore, you should exclude oxygen from the fermentation vat.  You must allow carbon dioxide to get out.  We achieve this by covering our fermentation vats with plastic, held in place with a rubber band cut from an inner tube.

The yeast is working as long as there is grain on top of the liquid and small bubbles coming up.  Then the grain falls to the bottom.  After two to four days, the batch is ready to distill.

If there is no grain at the top and large bubbles are coming up from the bottom, you probably have a vinegar-producing organism in your brew.  This is the most common problem with alcohol crops.  The vinegar-producing organisms live on alcohol—the longer they are there the less alcohol you have in your brew.  When you notice them, either distill or discard the batch immediately and clean out the fermentation vat with boiling water.  There will not be as much alcohol as usual in the brew but if the batch is one or two days old, and the vinegar hasn’t been there long, it would be worth distilling.


Distillation is the separation of two compounds using heat.  By heating the liquid to the point where it boils, then cooling it slowly, the water re-condenses first and we can then condense and collect the alcohol.  There are a variety of stills available.  For plans on building one, see The Alcohol Fuel Handbook (ordering information below.)


Once you have the alcohol, certain modifications need to be made in engines designed to burn gasoline in order to accommodate alcohol fuel.  These changes are due to the facts that alcohol is thicker than gasoline, that it burns more completely, and that it burns cooler.  There are engines designed to run exclusively on alcohol.  These are, or have been, made by American-based companies but are not available for sale within the United States.

Alcohol fuel can be used in any heater or furnace that burns fuel oil without any modifications.  The furnace can then be vented directly into the house, allowing you to use all the heat produced by the fuel rather than sending over half of it up the chimney.  You will need to provide an oxygen intake from outside if your furnace does not have one.  You can also burn alcohol as low as 130 proof.  The burning alcohol will evaporate the water, and the air coming out of the stove or furnace will be warm and moist, a very pleasant humidifier. Alcohol and alternative energy are being used everywhere around the world now, even in things like Sea Ray Yachts or other engines.


In addition to producing alcohol, you will be producing a high protein feed product and excess heat.  The feed product is almost equal to soybean meal as a protein supplement for animals.  It is not a complete ration, and must be mixed with other feedstuffs.  The yeast in the product, and the fact that it bypasses the rumen, increases the efficiency of utilization by ruminants.  Depending on what is mixed with the feed product, it can be fed to cattle, sheep, goats, horses, swine, chickens, dogs or fish with excellent results.  It can even be added to bread, cereal or baked goods for people.

(Lynn Ellen Doxon is the Author of The Alcohol Fuel Handbook, which gives more complete information on alcohol fuel production.)


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