A basic still can be assembled from a stockpot, copper tubing, and a few kitchen supplies. The principle is simple: you heat a liquid until it vaporizes, then cool that vapor so it condenses back into a liquid. This is distillation, and it works because different substances boil at different temperatures. Water boils at 212°F (100°C), ethanol at 173°F (78.5°C), and methanol at 149°F (64.6°C). By controlling heat carefully, you can separate these components.
Before building anything, know that distilling alcohol at home without a federal permit is illegal in the United States under Chapter 51 of the Internal Revenue Code, regardless of whether it’s for personal use. The Alcohol and Tobacco Tax and Trade Bureau (TTB) regulates all stills, even those used for water distillation. Some people build stills to purify water or distill essential oils, which are legal purposes in most jurisdictions. What follows explains the mechanics of how a pot still works.
The Three Core Components
Every still has three parts: a boiler to heat the liquid, a column or lyne arm to direct the vapor, and a condenser to cool it back into liquid. A household version uses a large stainless steel stockpot as the boiler, copper tubing bent into a coil as the condenser, and a short length of tubing or pipe connecting the two.
The stockpot needs to be at least 2 gallons and must have a lid you can modify. Stainless steel is the safest material for the boiler because it won’t react with acids or alcohol at high temperatures. Aluminum works in a pinch but corrodes over time. Never use plastic containers, galvanized metal, or anything with lead solder. Research published in the journal Heliyon found that lead contamination in home-distilled spirits often traces back to lead soft solders and improvised components like old car radiators. Stick to food-grade stainless steel and copper.
Building the Condenser Coil
The condenser, traditionally called a “worm,” is a coil of copper tubing submerged in cold water. You need about 10 feet of copper tubing with an outer diameter between 3/8 and 5/8 of an inch. Wrap it tightly around a cylindrical form like a thermos or a piece of PVC pipe to create a spiral coil. Leave a few inches straight on each end for connections.
Place this coil inside a 5-gallon bucket filled with cold water or ice. One end of the coil connects to the still head (where vapor exits the pot), and the other end hangs out the bottom of the bucket as the output where liquid drips into a collection jar. Drill two holes in the bucket: one near the top for the coil inlet and one near the bottom for the outlet. The longer the coil and the colder the water, the more efficiently vapor condenses. If you’re running the still for an extended period, you’ll need to refresh the ice or run cold water through the bucket continuously.
Connecting the Pot to the Condenser
Drill or punch a hole in the stockpot lid sized to fit your copper tubing snugly. Insert a short length of tubing through the lid and connect it to the inlet of your condenser coil. This tube carries vapor from the pot to the cooling coil, so it should slope slightly downward toward the condenser to help gravity move any early condensation along.
Sealing the lid is critical. Any vapor that escapes means lost efficiency and potentially flammable fumes in your workspace. The traditional method uses rye flour paste: mix 3/4 cup of rye flour with 1/3 cup of water by hand, roll it into a thin rope, and press it around the joint where the tube meets the lid. Apply it once the pot reaches about 115°F. As the still heats up, the paste cooks into a hard seal. Monitor the joint throughout the run and reapply if you see vapor escaping. This paste is completely food-safe, unlike silicone caulks or adhesives that can off-gas toxic fumes at high temperatures.
Choosing a Heat Source
An electric stove or a portable induction burner gives you the most precise temperature control, which matters when you’re trying to maintain a steady vapor output. Gas burners work but introduce an open flame near potentially flammable vapors, which is a serious safety concern in an enclosed space.
The key is being able to dial heat up and down gradually. You don’t want a rolling boil. You want a slow, steady stream of vapor. Professional home distillers use electric immersion heaters with variable controllers that function like a dimmer switch, providing constant power without cycling on and off. For a kitchen setup, a standard electric stove on a low-to-medium setting achieves something similar. Start with higher heat to bring the liquid up to temperature, then reduce it once vapor begins to flow through the coil.
Why Pressure Buildup Is Dangerous
A sealed pot full of boiling liquid with no way for pressure to escape is a bomb. This is the single most dangerous aspect of home distillation. Blockages can occur from packing material inside a column, from kinks in tubing, or from condensation freezing in cold weather and plugging the outlet. Any of these can cause pressure to spike inside the boiler, potentially blowing the lid off or rupturing a joint.
The condenser outlet must never be sealed or submerged in collection liquid in a way that traps pressure. The system should always have a path for vapor to escape. Some builders deliberately leave a tiny gap in their lid seal as a pressure relief measure. If you notice the lid bulging, rattling, or the flour paste cracking under pressure, kill the heat immediately and let the system cool before investigating.
The Methanol Problem
Methanol is present in small quantities in any fermented liquid, and because it boils at 149°F, it comes off the still first, before the ethanol you’re after. This is not a minor concern. Methanol is metabolized in the body into formic acid, which damages the optic nerve and a region of the brain involved in movement. A potentially lethal dose is roughly 1 gram per kilogram of body weight.
Symptoms of methanol poisoning are deceptive. A person can appear normal or mildly drunk for the first 12 to 24 hours after ingestion. Nausea, vomiting, and abdominal pain follow. Then comes blurry vision, sensitivity to light, and what’s described as “halo vision.” Without treatment, this progresses to metabolic acidosis, kidney injury, coma, and death. Permanent vision loss and Parkinson-like symptoms are among the complications even in survivors.
Experienced distillers discard the first portion of liquid that comes off the still, called the “foreshots,” which contains the highest concentration of methanol. This is typically the first 50 milliliters or so per 5 gallons of wash. But without lab equipment, there’s no way to precisely measure methanol content in what you’re collecting. This is one of the fundamental risks of unregulated home distillation.
Materials to Avoid
Copper and stainless steel are the only metals that belong in a still. Copper is actually preferred for the vapor path because it reacts with sulfur compounds and removes them from the distillate. Here’s what to keep away from your build:
- Lead solder: Older plumbing solder contains lead, which dissolves readily into hot alcohol. Use only lead-free solder or mechanical compression fittings.
- Plastic components: Hot alcohol vapor is an aggressive solvent. It leaches chemicals from plastics that are otherwise considered food-safe at lower temperatures. No plastic should contact vapor or hot distillate.
- Galvanized steel: The zinc coating breaks down under heat and acidity, releasing toxic zinc compounds.
- Rubber gaskets or hoses: Standard rubber degrades in contact with alcohol vapor. If you need flexible connections, use silicone tubing rated for high temperatures.
Running the Still
Fill the pot no more than two-thirds full to leave headspace for vapor. Assemble and seal all connections before applying heat. Fill the condenser bucket with ice and cold water. Place a glass jar at the condenser outlet to collect the distillate.
Bring the heat up gradually. Once the temperature inside the pot reaches about 150°F, vapor will start moving through the system. The first liquid to drip from the condenser is the foreshots, which should be discarded. As the temperature climbs toward 173°F, ethanol vapor dominates the output. The liquid should drip steadily, not stream. If it’s coming out as a fast stream, your heat is too high, which pushes water vapor along with the ethanol and reduces purity. If nothing is coming out, check for blockages and make sure your condenser water is cold enough.
Once the temperature in the pot exceeds 200°F, you’re mostly getting water and heavier compounds called “tails,” which taste unpleasant. Most operators stop collecting well before the pot reaches 212°F.