Rectified spirit is highly purified ethanol produced through repeated distillation, reaching a concentration of about 95.6% alcohol by volume. The remaining 4.4% is water, and this ratio exists because of a fundamental chemical limitation: standard distillation physically cannot push the concentration any higher. It serves as the base ingredient for many familiar alcoholic drinks, including vodka, gin, and liqueurs, and has wide use in cooking, perfumery, and industrial applications.
Why It Stops at 95.6%
Ethanol boils at 78.5°C and water boils at 100°C, so heating a mixture of the two should, in theory, let you boil off pure ethanol and leave the water behind. That works up to a point. But at a concentration of 95.6% ethanol by mass, the mixture forms what chemists call an azeotrope: a blend where the liquid and vapor have the exact same composition. No matter how many times you reboil and recondense at that concentration, the ratio stays locked. The boiling point of this azeotropic mixture is 78.2°C, actually slightly lower than pure ethanol’s boiling point.
To push past 95.6% and produce absolute (100%) alcohol requires different techniques entirely, such as adding a drying agent or using molecular sieves. For most beverage and industrial purposes, though, 95.6% is more than sufficient, and that ceiling is what defines rectified spirit.
How It’s Made
The process starts with fermentation. Yeast converts sugars from grains, grapes, sugarcane, or other plant sources into a low-alcohol liquid, typically around 5 to 15% ethanol. That liquid then enters a distillation column, a tall vertical apparatus where the mixture is heated from below. Because ethanol evaporates at a lower temperature than water, ethanol-rich vapor rises through the column while water-heavy liquid flows downward.
The first pass through distillation recovers roughly 66% ethanol. To reach 95%, the process is repeated or run through a column with many internal stages (called plates or trays), each one forcing another round of evaporation and condensation. At every stage, the rising vapor becomes slightly richer in ethanol. A well-designed continuous distillation column can take a dilute fermented liquid and produce 95% ethanol in a single pass through dozens of these internal stages. The result is a spirit so thoroughly purified that it carries almost none of the flavor or aroma of whatever was fermented to create it, which is why it’s also called “neutral spirit” or “neutral grain spirit” when made from grain.
Common Uses in Drinks and Cooking
Rectified spirit’s neutrality is its main selling point. Because it has virtually no taste of its own, it works as a blank canvas. Most gin starts as rectified spirit that is then redistilled with juniper berries and other botanicals. Blended whisky often includes a proportion of neutral spirit mixed with more flavorful malt whisky. Many liqueurs use it as a base, and cut brandy blends it with aged brandy to adjust strength and cost.
Home cooks and bartenders use it to make infusions like limoncello (lemon peel steeped in high-proof spirit) or crème de cassis (blackcurrant liqueur). The high alcohol concentration acts as a powerful solvent, pulling flavor compounds out of fruits, herbs, and spices much more efficiently than lower-proof options. In cooking, it can be used to extract or carry flavors in ways that water or wine cannot.
Rectified Spirit vs. Methylated Spirit
This is a critical distinction. Rectified spirit is food-grade ethanol, safe for drinking when diluted appropriately. Methylated spirit (also called denatured alcohol) is ethanol that has been deliberately made poisonous and undrinkable by adding toxic substances, most commonly methanol at concentrations of 5 to 10%. Other additives can include benzene, acetone, gasoline, or castor oil. The goal of denaturing is to make industrial alcohol unfit for consumption so it can be sold without the heavy taxes applied to drinking alcohol.
Methylated spirit is used as a cleaning solvent, fuel, and surface disinfectant. It should never be consumed. Drinking it can cause blindness, organ failure, and death, primarily due to the methanol content. If you see “rectified spirit” on a food or beverage label, that’s the drinkable version. If something is labeled “methylated,” “denatured,” or “industrial methylated spirit,” it is not safe to drink under any circumstances.
Health Risks of High-Proof Alcohol
Even though rectified spirit is technically food-grade, drinking it undiluted is extremely dangerous. At 95% alcohol, it can cause immediate chemical burns to the mouth, throat, and stomach lining. The body processes ethanol by converting it into acetaldehyde, a compound classified as a Group 1 carcinogen, meaning there is sufficient evidence that it causes cancer in humans. Acetaldehyde interferes with DNA repair, which is one mechanism behind alcohol’s link to at least seven types of cancer, including bowel and breast cancer.
Beyond cancer risk, high-concentration ethanol inflames the stomach lining (causing gastritis), damages the pancreas by activating digestive enzymes that attack the organ’s own tissue, and weakens heart muscle through oxidative stress. Chronic heavy use depletes thiamine (vitamin B1), which can cause severe, sometimes irreversible brain damage. The World Health Organization’s position is that no level of alcohol consumption is entirely without health risk. For children, ethanol can cause acute poisoning at very small doses.
In practice, rectified spirit is almost always diluted before anyone drinks it. Vodka, for example, is typically rectified spirit cut with water to reach 40% alcohol by volume.
Fire Safety and Storage
Rectified spirit is highly flammable. Pure ethanol has a flash point of about 13°C (55°F), well below typical room temperature, meaning it can ignite from a spark or open flame at any point in normal conditions. Even a 40% alcohol solution has a flash point of just 26°C (79°F). Vapors from high-proof spirits are heavier than air and can travel along floors to reach ignition sources some distance away.
If you’re storing rectified spirit at home, keep it in a tightly sealed glass container away from heat sources, open flames, and direct sunlight. In professional distillery settings, safety requirements include explosion-proof lighting, mechanical ventilation systems designed to keep vapor concentrations below 25% of the lower flammable limit, emergency shutoff systems, and fire sprinklers. Open flames, including candles and catering warmers, are prohibited in areas where high-proof spirits are stored or handled.