Classics: Bourbon/American

Other Bourbon/American Classics:
Char | Copper

It ain't easy being bourbon. You've got to be a minimum of 51% corn to start with. There are all sorts of tedious rules and measures about what strength you're allowed to be when and where; so strong coming out of here, no stronger than this going into there, and then there's that 40% ABV into the bottle thing. You always have to be in new charred oak barrels; they even have rules about how long you have to be in the barrels. Sorry, not rules, it's federal law. And don't ask about the taxes; you'll get a headache.

Which makes it such a shock to find out that the two distilleries that make Tennessee whiskey-Jack Daniel, in Lynchburg, and George Dickel, not far up the pike, outside of Tullahoma-do all that...and one more thing. Tennessee whiskey also goes through the Lincoln County Process, an amusingly modern-sounding name for a technique that's almost 200 years old. It's known by a variety of names: the Lincoln County Process, charcoal mellowing, leaching, or as Jack Daniel publicist-raconteur Roger Brashears puts it, "smoothing out the hog tracks."

Call it what you want, at its heart it is a simple process: every drop of Tennessee whiskey has to trickle its way through ten feet of hardwood charcoal before going in the barrel to age. Simple, but maybe a bit tricky: George Dickel master distiller David Backus says that "The Lincoln County Process can ruin good whisky, and it can't make bad whisky good."

Don't confuse the Lincoln County Process with chill-filtering before bottling, or the rough filtering whiskey gets when it's dumped from the barrel. This is a slow, days-long charcoal filtering of the new make, the "white dog;" a process that hasn't varied much since it began in the early 1800s. Something like that deserves a closer look.

Firing Up the Process
The Lincoln County Process is generally attributed to a man named Alfred Eaton, who started using the technique in the mid-1820s...maybe. Eaton's invention of the Lincoln County Process has a somewhat stronger basis than some other bits of American whiskey history-we know for certain that Eaton was a commercial distiller, who at one time had his still in the same Cave Spring that is at the heart of the Jack Daniel distillery-but it is not as solidly based in documented fact as something like Dr. James Crow's standardization of the sour mash process. It may have been Eaton's invention, or he may have put his name on something that was already being done by the local distillers. As Jack Daniel's biographer, Peter Krass, puts it in Blood & Whiskey, this is "potentially another fish story-or, to use a fancier word, apocrypha."

Eaton or no Eaton, Tennessee whiskey makers have been using the Lincoln County Process for so long that the only two distilleries left that use it aren't in Lincoln County anymore. Like Bourbon County in Kentucky, Lincoln County isn't nearly the size it used to be. "This was Lincoln County," Jack Daniel master distiller Jimmy Bedford said as he tramped up the hill to the distillery's rick-burning area. "They carved Moore County out of it in 1870."

Just because the Lincoln County Process is simple doesn't mean that it's not exacting. Bedford explained how the distillery gets the wood it uses for the charcoal. "We're looking for sugar maple trees that grow in gladey areas," he said. "You get an abundance of ply in those shady areas." Ply is a reference to the growth rings; trees in shade grow more slowly, meaning more plies, and thus more cellular chambers to make holding areas in the charcoal. "Sugar maple burns well," Bedford continued, "and it has the sugars we're looking for. We have experimented with other hardwoods, but sugar maple works best for our purposes.

" We buy the trees already cut up," he said. "They're naturally dried, air-dried." The trees are cut in the fall, to avoid sap pockets that might pop and flare in the charcoal burning. The dried wood is sawed to four-inch by four-inch billets, about five feet long. These are then stacked into "ricks" by laying six billets side-by-side, with about a 6" gap between them; another such layer is laid on crossways, and so on, up to six to eight feet high. The ricks are set in squares of four, with a centrally-inclined lean so that they'll collapse inward as they burn, rather than fall apart.

When it's time to burn, the ricks are sprayed with alcohol and set on fire. They are burned in the open air, but at Jack Daniel, they burn under large, rectangular metal hoods that channel the smoke away.

Traditionally, charcoal was made by slow, controlled smoldering fires in an earth kiln. Tennessee distillers burn in the open to get impurities out of the wood that would remain in kilned charcoal. What kind of impurities? According to Dr. Peter J. F. Harris, of the Department of Chemistry at the University of Reading in the UK and an expert on the structure of charcoal, "many volatile compounds will be released when wood is heated to high temperatures, some of them harmful, notably methanol."

" We'll let it burn for two or three hours," said Bedford, "and wet it with hoses to control the burn." If the burn weren't controlled with sprays of water, the fire would quickly consume the wood, leaving only ashes behind. Too much water and the fire will go out in spots, leaving wood in the charcoal. Neither is much good for the Lincoln County Process. The fire burns hot, but the tenders never let it get roaring. Once the burning is over, the charcoal is allowed to cool before being broken up to pieces about the size of a large pea.

Mellowing Out
At this point, it's ready for the vats, the "mellowing vats," which certainly sounds a lot better than "leaching vats." This is where things at Dickel and Daniel take a different turn.

The vats at Jack Daniel are five feet in diameter and ten feet deep, with about eight feet of charcoal in them. Across the top are two crossed arms, hollow metal tubes with drip holes where the new-make whiskey emerges to drip onto the charcoal bed. The whiskey rips...drips...drips, and seeps down into the vat, dripping out through a plain white wool blanket-white when it's first placed there, anyway-at the bottom. "The charcoal will last about six months," said Bedford. "We get a flow of about eight to ten gallons a minute out the bottom. There's about a 1% loss in the mellowing process."

Outside of Tullahoma, things are done a bit differently. To begin with, the mellowing is done cold. "We do cold chill mellowing," David Backus explained. "People noticed that the whisky we made in the winter tasted better. There is a big difference between cold and warm mellowing." Every vat at Dickel is refrigerated to simulate winter temperatures. There is also a blanket at the top and bottom at Dickel, and the whisky (Dickel uses the Scottish spelling) trickles down through a perforated steel plate onto that top blanket.

The most noticeable difference, though, is under the top blanket. "The charcoal bed is drowned," Backus said. When a new bed of charcoal is loaded in a vat, the bottom of the vat is closed off, and whisky seeps into the entire bed until the vat is full, brim-full. That's when the whisky is allowed to trickle out the bottom. "That way," Backus explained, "the whisky hits every spot of the bed. If it trickles down, drop by drop, the whisky will make a path down through the charcoal, and it's going to miss some parts of the bed; those parts will never get used, and the parts in the path get over-used."

Backus changes a bed after about a year. Like Bedford, he makes the decision on when to change a bed based on the taste of the whisky coming out the bottom, not by a mark on a calendar. "Some beds go longer, some less," he said. "Most are about a year." A new bed will strip too much out of the whisky, Backus believes, and that new bed's output will have to be set aside for a time till it gets settled in.

Corn de vie
Looking inside the vat is where the simple process turns complicated. It would seem on first look that all the bed is doing is stripping out flavor. Isn't that what all the sound and fury over chill-filtering is about? David Backus very kindly set up a tasting of Dickel new make that made the Process come alive.

First up was a sample straight off the beer still, a common column still, same as is used at Jack Daniel and at most Kentucky bourbon distilleries. The sample was grainy, muddled in aroma and flavor, as if it couldn't decide what it wanted to be. The next was off the doubler. It was remarkably cleaner, both to the eye in the glass and on the palate in the mouth, and was unmistakably the taste of sweet, pure corn; no longer undecided at all.

The third sample was off the mellowing vat, and it was the corn from the doubler lightened, almost a corn eau de vie. The mellowing vat had pulled off the corn's oiliness, the heavy down-home cooking character of the corn, and left behind only the corn's spirit. The "hog tracks" were gone.

Where did they go? They were buried in the charcoal. Charcoal-burning is an ancient human art, going back at least 5,000 years, and humans used charcoal as far back as 30,000 years ago for art, cave-wall drawings. Charcoal's filtering and adsorbent qualities were probably discovered around 4,000 years ago. Dr. Harris cites early uses of charcoal as a filtering agent in his paper, "On Charcoal" (Interdisciplinary Science Reviews, V.24, N.301, 1999). "Egyptian papyri from around 1500 BC describe the use of charcoal to adsorb malodorous vapors from putrefying wounds, and there is an Old Testament reference (Numbers 19:9) to the ritual purification of water using the charred remains of a heifer."

The charcoal you hear most about today in terms of filtering is activated charcoal, charcoal that has been exposed to 1,000°C steam. "Concerning the filtering effectiveness of non-activated charcoal, this would be much less than activated," Dr. Harris explained. "The non-activated form would have a lower surface area-a very approximate figure would be a few hundred meters squared per gram, compared with up to 1500 meters squared per gram for activated. I have no idea why Jack Daniel's does not use activated." Remembering Backus's comments about new charcoal stripping out too much from the whiskey, it seems likely that activated charcoal would strip out the hog tracks, the mud they were made in, and the pig himself, squeal and all.

So instead the two distilleries, very different in some ways as Jack Daniel's roars with activity making the world's best-selling whiskey while Dickel quietly makes whiskey the way David Backus wants to, both stick to a process that has changed little in almost two hundred years. It is, in large part, a very "hand-made" part of Tennessee whiskey: the wood is stacked by hand, burned under human control, and the charcoal is replaced when the whiskey it produces no longer tastes right to the respective master distillers.

More modern methods are doubtless available, but you never, ever mess with something that works well when it comes to making whiskey. "We ain't gonna kick a pulling mule," as Roger Brashears puts it. Let the ricks flame and smolder, and let the whiskey trickle. The Lincoln County Process is as much a part of Tennessee whiskey as corn or white oak barrels.

Other Bourbon/American Classics:
Char | Copper