You can get ethanol by buying it commercially in various grades, producing it through fermentation, or in some cases synthesizing it from industrial chemicals. The right approach depends entirely on what you need it for. Ethanol sold as a cleaning solvent, a fuel additive, a lab reagent, and a beverage-grade spirit all differ in purity, additives, and legal requirements.
Buying Ethanol Off the Shelf
The fastest way to get ethanol is simply to purchase it, but the grade you need matters. Ethanol is sold in several distinct categories, each regulated differently and suited to different jobs.
Denatured ethanol is the easiest to buy. Available at hardware stores, pharmacies, and online retailers, it contains small amounts of additives that make it undrinkable. The most common denaturant is methanol, typically at 5 to 10 percent, which is why denatured ethanol is sometimes called “methylated spirits.” Other possible additives include isopropyl alcohol, acetone, pyridine, and a powerful bitter agent called denatonium benzoate. Because it’s unfit for consumption, denatured ethanol is exempt from beverage alcohol taxes and requires no special permit to buy. It works well for cleaning, fuel, and many solvent applications, but it is toxic if swallowed.
Food-grade ethanol is consumable-quality alcohol made from grain, sometimes labeled “grain neutral spirits.” It meets standards set by the Food Chemicals Codex and falls under FDA oversight. You can purchase it from specialty chemical suppliers, though some states restrict sales of high-proof spirits to licensed retailers. Beverage-grade ethanol (vodka, Everclear, and similar high-proof spirits) is the most accessible form of food-grade ethanol and can be bought wherever liquor is sold legally.
USP-grade ethanol meets pharmaceutical standards and is used in hand sanitizers, drug formulations, and mouthwash. ACS-grade ethanol meets American Chemical Society purity specifications for laboratory and analytical work. Both are available through laboratory supply companies, but purchasing undenatured ethanol at 190 proof or higher triggers federal excise tax obligations. Certain organizations, including government agencies, universities, hospitals, and research labs, can apply for a Tax-Free Alcohol User permit through the Alcohol and Tobacco Tax and Trade Bureau (TTB) to obtain it without paying the tax.
Making Ethanol by Fermentation
Fermentation is the oldest and most common way to produce ethanol. Yeast cells consume sugar and convert it into ethanol and carbon dioxide under low-oxygen conditions. The workhorse species is Saccharomyces cerevisiae, the same yeast used in bread, beer, and wine. It accounts for the vast majority of the world’s annual ethanol output, which now exceeds 100 billion liters.
This yeast grows best between 25°C and 30°C (roughly 77°F to 86°F), though temperatures in large-scale distilleries can climb to 38°C. It ferments glucose efficiently but cannot break down the five-carbon sugars (pentoses) found in woody plant material. A typical fermentation run takes 30 to 40 hours at those moderate temperatures.
The sugar source, or feedstock, determines both the process complexity and the yield. The two dominant feedstocks globally are corn starch and sugarcane. Corn requires an extra step called saccharification, where enzymes break the starch into fermentable glucose before yeast can work on it. Sugarcane juice already contains simple sugars and can go directly into fermentation. Other starchy or sugary crops like potatoes, sweet potatoes, sugar beets, and sweet sorghum also work. Cellulosic biomass from grasses, wood, and agricultural residues represents a newer frontier but requires specialized microorganisms or pretreatment to unlock the sugars trapped in plant fiber.
At the end of fermentation, you typically have a liquid (called a “wash” or “beer”) containing roughly 8 to 15 percent ethanol by volume. To concentrate it further, you need distillation.
Concentrating Ethanol Through Distillation
Distillation exploits the difference in boiling points between ethanol and water. Ethanol with a small percentage of water boils at approximately 173°F (78°C), while pure water boils at 212°F (100°C). By heating the fermented liquid, ethanol vaporizes first, rises through a column, and condenses back into a much more concentrated liquid.
There is a hard ceiling, though. Standard fractional distillation can only concentrate ethanol to about 95.6 percent by weight. At that point, ethanol and water form what chemists call an azeotrope: a mixture that behaves as a single substance during boiling, with the vapor and liquid having the same composition. No amount of additional distillation passes will push the concentration higher.
For most practical purposes, 95 percent ethanol is more than sufficient. Hand sanitizers are effective at concentrations between 60 and 95 percent, according to the CDC. Fuel ethanol blended into gasoline also works fine at this purity for lower blends. But certain industrial and laboratory applications require completely water-free (anhydrous) ethanol at essentially 100 percent purity.
Getting to 100 Percent With Molecular Sieves
To break past the 95.6 percent azeotropic barrier, producers use a process called adsorption rather than more distillation. The most common method involves molecular sieves: tiny synthetic beads with uniform pores just large enough to trap water molecules while letting ethanol molecules pass through.
Type 3A molecular sieves perform best for this job. Their pore openings are about 3 angstroms wide, perfectly sized to capture the smaller water molecule while excluding the larger ethanol molecule. When 95 percent ethanol is passed through a bed of these sieves, the water gets pulled out and held on the sieve surface. The result is anhydrous ethanol at 99.5 percent purity or higher. Once the sieves become saturated with water, they can be regenerated by heating, making the process reusable. Some researchers have also explored biobased adsorbents like processed corncobs and palm stone, though synthetic sieves remain the industry standard.
Synthetic Production From Ethylene
Not all ethanol comes from biological sources. Synthetic ethanol is manufactured by reacting ethylene (a petroleum-derived gas) with water in a process called direct hydration. This occurs at high temperatures and pressures in the presence of a catalyst. Older facilities used liquid acid catalysts like phosphoric or sulfuric acid, while modern plants use solid catalysts. The ethylene feedstock typically arrives via pipeline at pressures around 5,000 kPa (roughly 725 psi).
Synthetic ethanol is chemically identical to fermented ethanol, but it’s generally restricted to industrial uses like solvents, coatings, and chemical manufacturing. It isn’t approved for food or pharmaceutical applications in most jurisdictions because of potential trace contaminants from the petroleum-based starting material.
Legal Rules for Producing Ethanol
In the United States, distilling ethanol is federally regulated regardless of the intended use. The TTB requires anyone operating a distilled spirits plant to apply for and receive a permit before starting. There is no fee to apply at the federal level, and applications can be filed online through the TTB’s Permits Online system. However, the documentation requirements vary based on your business structure and the type of permit.
Home distillation of beverage alcohol is illegal at the federal level without a permit, even for personal use. This stands in contrast to home brewing of beer and wine, which is permitted in limited quantities. If you want to produce ethanol strictly as fuel, you can apply for a federal fuel alcohol permit, which has a simpler approval process than a beverage permit. State and local laws add another layer of regulation and vary significantly, so the federal permit alone may not be sufficient depending on where you live.
Choosing the Right Grade for Your Purpose
For surface cleaning and disinfection, denatured ethanol from a hardware store at 70 percent concentration or higher handles most jobs effectively. The CDC notes that alcohol-based sanitizers work best in the 60 to 95 percent range for killing germs on hands.
For use in food products, extracts, tinctures, or anything that might be ingested, you need undenatured, food-grade ethanol. Purchasing high-proof undenatured ethanol outside of a liquor store typically requires navigating excise tax rules or holding a TTB permit.
For laboratory and analytical work, ACS-grade ethanol provides the documented purity and low impurity levels that reproducible experiments demand. For pharmaceutical manufacturing or compounding, USP-grade ethanol is the standard, carrying tighter specifications and FDA-registered production oversight.
For fuel blending or small engine use, denatured ethanol or specially permitted fuel ethanol is appropriate. The purity requirements for fuel are less stringent than for consumption, and the regulatory path through a fuel alcohol permit is more straightforward than a beverage spirits permit.