Why Copper Stills Make Cleaner Spirits: Sulfur, Lead Solder and the Four Cuts

Every Proper Lecture Begins with a Tax

I write this at Fort Wilkins, on the Suncook Valley Turnpike in Pittsfield, Merrimack County, New Hampshire, with a jar filling drop by drop beside me and Barnaby, my black bear, grunting at the end of his chain outside the cabin window. He has been promised a ham bone if he behaves himself until I am finished. My subject is copper, and I mean to treat of it until your ears ring like brass. I will put it in words a mule skinner can follow, for every reader who stands at his own apparatus is an alchemist and natural scientist whether he owns the title or not.

Every proper lecture begins with someone getting taxed. In the early 1860s Mr. Lincoln's government brought forth the Revenue Act, and of a sudden every kettle in New England became a matter of federal concern. Men who had been quietly turning cider and grain into spirit since before the Revolution found themselves the subject of paperwork, inspectors, and fellows with ledgers and bad attitudes. Did any of them quit? They did not. They hid the still better, and they cared a great deal more for the quality of what came out of it, for a customer who buys a poor jar once does not come back, and a customer who does not come back does not pay your fine.

Copper was the answer, and it had always been the answer, long before any of us knew why. The old Scotch, Irish and French distillers swore by it. Copper made the spirit sweet, they said; iron made it sour; a still without copper was a crime against the palate. They were right, though not one of them could have told you the chemistry. They knew only what their noses told them.

The Copper Sentinel: Why the Metal Sweetens the Spirit

An alchemist is merely a man who is curious and does not know when to stop. I took the old rule and asked the question the old men never asked: why? I stood at my anvil with a sample of sour spirit, a strip of bright copper, and a great deal of patience, and here is what I found.

When you heat a mash, the yeast has done more than make alcohol. It has also thrown off a little sulfur, and with it the mercaptans, the most foul-smelling vapours known to man. Rotten egg. Boiled cabbage. A Concord politician's breath after a long committee meeting. That is mercaptan, and it rides the steam out of the pot like a drunk on a stagecoach, and if nothing stops it, it ends in your jar.

Here is the marvel: copper stops it. When those sulfur vapours touch bright, clean copper, the sulfur bonds with the metal and forms copper sulfide, which stays behind upon the surface. The vapour travels on up and over, and what comes through on the far side is sweeter, cleaner, and purged of its stink. The copper is not merely a pot. It is a working chemist standing sentinel inside the apparatus, catching the villains as they pass. I call it the Flame-Flow Copper Heat Invention, and I will not be denied the credit.

Hammered, Heavy and Pure, and Never Joined with Lead

Why hand-hammered, and why twenty-four ounce? Hammering work-hardens the copper and gives a dense, even sheet. Twenty-four ounce is heavy gauge; it holds heat evenly, it does not scorch, and it will outlast a stack of cheap tin kettles the way Barnaby will outlast a deputy. And it must be electrolytic copper, refined by an electric current to a very high purity. Salvaged copper, cheap copper, copper with lead and arsenic and who-knows-what hiding in it, is a poisoner's metal. I have pulled enough teeth from men who thought they could save a dollar to know that cheap is the most expensive word in the language.

On joinery I would rather bore you than bury you. Never use lead solder on a still. Lead is a poison that sickens and kills, and contamination from sloppy joints is a documented hazard of every illicit run that ever went wrong. Silver solder, or proper mechanical unions, and nothing else. Nor should any man make a still from a salvaged radiator or any scrap of metal whose history he does not know. I have seen what that does to a man, and I will spare you the particulars in case you are at supper.

Then there is cleaning. A copper still never cleaned is like a Methodist's conscience: shiny on the outside, green and crusted where nobody looks. After every run, rinse the pot and scrub it bright. That green crust is copper sulfide and verdigris; it dulls the active surface, and worse, it may flake into your product. Keep your copper clean, and your copper will keep you honest.

Reading Heat by Colour and Feather

I lately entertained Mr. Junior Vance, a retired bootleg runner out of North Wilkesboro, in Wilkes County, North Carolina, who drove modified Ford coupes down out of the Brushy Mountains to Charlotte and was known up and down those hills as the fastest hand on a mountain road. He asked whether Barnaby bites. I told him Barnaby has bitten two dentists, a surveyor and a lightning-rod salesman, and was perfectly polite to all of them.

Junior learned heat before he learned speed, at the bellows of his grandfather's forge. The old man bade him watch the colour: copper glows cherry-red first, then straw, then silver, and each means something different. Junior fancied himself smarter than his grandfather and guessed instead, and ruined a whole batch of barn hinges, every one of them wrong. Murdered by pure vanity, I call it. But a man who learns his colours the expensive way never forgets them.

A gentler teacher was a neighbour down the road, who held a hen feather near the hot metal. As Junior told it, "If that feather curled up like a question mark, you were ready. Too soon and it just lay there, too late and it was a puff of smoke and a bad smell." The cheapest thermometer in the Brushy Mountains, he said, and it never once lied to him. It is the most scientific instrument in all of poultry, and the only one that lays its own replacement. I intend to steal it.

Heat followed him onto the road as well. A fellow bet him he could not have hot coffee on a long run without stopping, so Junior set a tin of coffee atop his engine manifold and put his foot down. By the time he came roaring through Statesville the tin was boiling like a kettle at a church supper, and he collected every dollar. His one piece of wisdom for young men I set down entire: "If you hit the ditch at eighty, boy, make sure you duck below the steering wheel." There is more sense in that than in the whole Concord legislature.

The Four Cuts of a Run

A run is not one thing. It is four, and they come off the still in order. The whole art lies in knowing where one ends and the next begins.

First come the foreshots, the very first vapours, carrying methanol and harsh volatile compounds. I say it with the weight of a man who has pulled teeth for forty years: foreshots are poison. They are discarded. Never drunk, never rinsed in a mouth, never given to a friend, and you will not argue with me about it.

Next come the heads, still harsh, smelling of solvent, and good for a headache you could hang a hat on. These too are discarded. Some keep them for cleaning or lamp fuel, and that is their affair, but none of it goes in a glass.

Then the hearts: the prize, the clean, sweet centre of the run, where the copper has done its work, the sulfur is gone, and the spirit comes over smooth. Judge it by smell, by taste in the smallest quantity, by patience and by experience. A beginner wants to collect too much. A master stops early and starts late.

Last come the tails, as the run winds down: heavier compounds, oily and bitter, tasting of wet cardboard and old sweat. Cut them off and set them aside; in a proper operation they are redistilled with the next batch to recover what good remains.

Foreshots out. Heads out. Hearts in. Tails out. And I repeat what I must: making distilled spirits for drinking without a federal permit is against the law of the United States, and what I set down here is for history and education only. Practise the craft lawfully, with proper permits, for a bear cannot pay your fines, though Barnaby has offered.

Mind the fire as well. Alcohol vapour is flammable; a leak, a loose union, a spark in the wrong place, and you have a fire no bucket will master. Keep your fire low, your joints tight, and a wet blanket, a clear head and a clear exit at hand. A careless distiller is not a distiller for long, and not much of anything afterward.

Hickory Ash and the Thump Keg

I keep a steel punch at my anvil for stamping G. G. WILKINS, PITTSFIELD N.H. onto good copper cents. Hard money was scarce in the war years, and a man who stamped his name on a coin told the world that his word and his copper were both good. One such cent goes to Mr. Cletus Miller of Wilkesboro, North Carolina, called Rabbit, whose uncle swears the old-timers threw hickory ashes or red oak shavings into the thump keg to clean out bad heads.

There is a thread of truth in it, tied into the wrong knot. Hickory and oak are hardwoods, and burned to charcoal they make a fine adsorbent. Charcoal has a vast surface, and filtering a finished spirit through it will pull out some harsh and oily compounds; old distillers did it for good reason. But that is charcoal filtration of a finished product, not ash dropped into a boiling pot.

Ash in the thump keg removes no methanol and mends no bad head. Methanol boils over early, and no handful of hickory ash will catch it. The only cure is to make your cuts properly and keep the heads out of the jar. The uncle's ash likely does no harm, but it does no good either, and he has been fooling himself for forty years. I say so with affection.

So keep your copper clean, your cuts honest, and your fire low. Barnaby has earned his ham bone, and I bid you goodnight from Fort Wilkins.