Distillation concentrates alcohol by exploiting the fact that ethanol boils at 78.4°C while water boils at 100°C: a single distillation of a wash at 10% ABV typically yields a distillate of 35–50% ABV, and a second pass can reach 60–75% ABV. Discarding the first 50–100 mL per 25 liters as foreshots improves flavour but is not a safety control, because methanol is spread through almost every fraction; the control is the feedstock, since fruit and pomace carry far more methanol than grain or sugar. For antiseptic use dilute to 70% ABV; for drinking spirits, dilute raw distillate to 40–45% ABV with clean water.
Part of Food Processing
Distillation concentrates alcohol and volatile compounds by exploiting their lower boiling point relative to water. A properly constructed still can produce spirits for medicine, fuel, sterilization, and trade from any fermented beverage. Understanding the principles — and the safety hazards — is essential before attempting construction.
Distillation was known to ancient Mesopotamians and Greeks and was refined into a sophisticated technology by Arab alchemists in the 9th-10th centuries. The word “alcohol” derives from the Arabic “al-kuhul.” Medieval European alchemists and physicians used distilled spirits primarily as medicine — “aqua vitae” (water of life) — long before recreational distilling became common. In a rebuilding civilization, distillation provides antiseptic, fuel, preservation medium, anesthetic, and currency in one vessel.
The Principle
Alcohol (ethanol) boils at 78.4 degrees C; water boils at 100 degrees C. When you heat a fermented liquid (wash), the vapor produced is richer in alcohol than the liquid. By capturing, cooling, and condensing this vapor, you collect a liquid with higher alcohol concentration than the starting wash.
A single distillation of a wash with 10% alcohol by volume (ABV) typically produces a distillate of 35-50% ABV. A second distillation (double-distilling) can push this to 60-75% ABV. Triple-distillation can reach 80-85% ABV.
What cannot be removed: Methanol (wood alcohol) boils at 64.7 degrees C — slightly lower than ethanol — but distillation does not separate it out. It is produced in small quantities by fermentation, most in pectin-rich fruit, and it is present in almost every fraction of a run, not only the foreshots. Pure methanol is toxic: as little as 4 mL can cause blindness, and a lethal case is reported at about 6 mL (4.7 g), though sources disagree on the lowest lethal amount. Those are doses of pure methanol, not of spirit. Discarding the foreshots improves flavour; it does not remove the methanol. See Methanol Hazards.
Components of a Simple Still
The pot (boiler or cucurbit): Any heat-safe vessel that can be sealed. Copper is traditional and superior — it reacts with sulfur compounds in the wash, removing unpleasant flavors. Clay pots work but limit inspection. Steel or iron works for functional distillation. Capacity: 10-50 liters for a small community still.
The head (onion head or dome): Fits on top of the pot and collects vapor. Shaped like an inverted bowl or onion. The shape affects flavor — a tall head allows more reflux (falling-back of heavier compounds) and cleaner spirits.
The lyne arm (swan neck): A pipe or tube connecting the head to the condenser. Angled downward so condensate flows toward the condenser, not back into the pot.
The condenser (worm or coil): A coiled tube immersed in cold water. Vapor enters the top of the coil, contacts the cold metal, condenses to liquid, and flows out the bottom. The longer the coil and the colder the water, the more efficient the condensation.
The collection vessel: Receives the distillate. Should be clean, non-reactive, and easy to seal.
Building a Basic Clay/Copper Still
Materials:
- Copper pot or clay vessel (10-20 liters) with lid or sealed top
- Copper or clay tube for the lyne arm (2-3 cm inner diameter)
- Copper coil (5-8 m of copper tube, 1.5-2 cm inner diameter, coiled into a 20-30 cm diameter spiral)
- Clay or lard seal for joints
- Barrel or trough for cooling water
- Fireplace or fire control system
Assembly:
- Fit the head to the pot using clay seals. All joints must be vapor-tight — any steam escaping is product lost and a fire hazard.
- Attach the lyne arm to the head, angled downward at 20-30 degrees
- Run the lyne arm into the top of the cooling barrel
- Coil the copper tube inside the barrel (the condenser coil)
- Run the outlet of the coil down through the barrel bottom and out to the collection vessel
- Fill the barrel with cold water; arrange a way to refresh it (drip feed from higher reservoir, or manual bucket filling)
Testing for leaks: Fill the assembled still with water and heat gently. Watch all joints for drips or steam escaping. Seal any leaks with clay, lard mixed with flour, or a commercial food-safe sealant.
The Wash (Feedstock)
Any fermented beverage can be distilled. The quality of the final spirit depends significantly on the quality of the wash:
| Source | Approximate ABV | Yield per 100 L wash |
|---|---|---|
| Apple cider (hard) | 6-8% | 6-8 L at 40% ABV |
| Grain wash (beer) | 5-8% | 5-8 L at 40% ABV |
| Grape wine | 10-14% | 10-14 L at 40% ABV |
| Sugar wash (molasses/beet) | 10-15% | 10-15 L at 40% ABV |
| Honey mead | 10-14% | 10-14 L at 40% ABV |
The wash should be fully fermented (no more active bubbling) before distillation. Distilling an actively fermenting wash creates pressure in the sealed system and risks explosion.
The Distillation Run
Step 1: Load and heat slowly Fill the pot with wash (maximum 2/3 full — allow space for expansion and turbulence). Apply heat gradually. Rushing to high temperature causes foaming and carries suspended solids over into the distillate (called “puking”).
Step 2: Collect foreshots The first distillate to emerge is the foreshots — rich in acetaldehyde, ethyl acetate, and other harsh-smelling volatiles. Discard the first 50-100 mL per 25 liters of wash for flavour; this is not a safety step and it does not remove methanol (see Methanol Hazards). In practice, the foreshots smell like nail polish remover or solvent — when this smell clears and you begin to smell a cleaner, sweeter vapor, you are transitioning to the heads.
Step 3: Collect heads After foreshots come the heads — still somewhat harsh, with solvent notes. These contain desirable esters but also significant congeners. Collect separately (100-200 mL per 25 L of wash). Heads can be redistilled or added back to the next batch.
Step 4: Collect the hearts The heart of the run — the clean, palatable spirit — typically represents 30-50% of the total distillate. It smells clean, sweet, and of the source material (fruity for cider, grainy for grain wash). Collect this fraction as your primary product.
Step 5: Collect tails As the run progresses, the distillate weakens and takes on wet cardboard, mushroom, or oily notes — these are the tails. Collect separately. Tails can be added back to the next batch’s wash to recover alcohol.
Step 6: Clean up When the distillate stream nearly stops and the temperature in the pot rises noticeably above 95 degrees C, the run is essentially complete. Stop the fire. Allow the still to cool before opening.
Dilution and Testing
Raw distillate from a pot still is typically 40-70% ABV. For drinking spirits, dilute to 40-45% ABV using clean water. For antiseptic use, 70% ABV is optimal (higher concentrations are less effective for sterilization).
Field-testing ABV without instruments:
- Float test: A well-made hydrometer measures specific gravity and allows ABV calculation
- Burn test: If spirit burns with a blue flame and leaves the cotton it soaked slightly damp, it is roughly 50-60% ABV. If cotton burns completely dry, it is higher. If it will not light, it is below 40% ABV.
Safety Rules — Non-Negotiable
- Never distill in a sealed system without a pressure relief. Pressure buildup causes explosions. The collection end of the condenser must be open to atmosphere.
- Never heat a still over an open flame without supervision. Ethanol vapor is highly flammable. Use indirect heat (hot water bath, enclosed stove) whenever possible.
- Choose the feedstock for safety; discard the foreshots for flavour. Methanol poisoning is real, it comes from the feedstock (fruit and pomace carry far more than grain or sugar), it is spread through the whole run, and it shows 12 to 48 hours late. The first 50-100 mL per 25 liters is still worth discarding for taste, but it is not what makes a spirit safe. See Methanol Hazards.
- Do not use lead solder or lead-containing alloys. Lead dissolves into acidic distillates and causes cumulative poisoning.
- Keep ignition sources away from condensate collection. The collection vessel sits in a pool of alcohol vapor.
Distillation, practiced safely and with attention to cut points, produces a product with enormous utility for a rebuilding community. A small community still processing surplus fruit or grain each autumn can provide a year’s supply of antiseptic, fuel for oil lamps and engines, and a trade good of reliable value.