"Take a deep breath; you'll feel a whole lot better," promises Sammy Gulley, leading the way into a warehouse at the Jack Daniel's Distillery. Inside, the fumes from 20,000 barrels almost knock you off your feet.
It is here, at this site deep in rural Tennessee, that every bottle of the famous sour mash whiskey is produced. Visitors are shown each step of the operation, including the unique "charcoal-mellowing" process said to give Jack Daniel's its distinctive flavour. But be warned: this is strictly a sniffing tour. The only liquid refreshment on offer is a glass of lemonade.
By a quirk of history, America's oldest registered distillery is located in bone-dry Moore County, where the sale and public consumption of alcohol are forbidden by law. The nearest liquor store is situated across the county line in Tullahoma - "11 miles, seven paces and one screen door away", according to Roger Brashears, the company's laconic promotions manager.
Jack Daniel, who set up business on the outskirts of the tiny town of Lynchburg in 1866, must be turning in his grave at this lamentable state of affairs. Mister Jack, as they call him locally, was mighty partial to a drop of his own product. Happily for him, he died before Prohibition brought down the shutters.
His successors are only too pleased to show people around, and the distillery has become one of Tennessee's biggest tourist attractions. A quarter of a million visitors descend every year, mainly on day trips from Nashville, 80 miles to the north east.
The black-and-white posters in the long-running advertising campaign evoke the atmosphere of a bygone era, of old-timers in dungarees cranking out the whiskey drop by drop. Gratifyingly, it really is like that: a quiet, unhurried, low-tech operation. In fact, all the people who appear in the ads are real-life employees - Jack Bateman, for instance, who runs the brickyard where the charcoal is produced. Bateman, who has chalked up 42 years of service with the company, was spotted near the sawmill, chewing on a blade of grass, lost in thought.
Jack Daniel chose the site because of a limestone cave spring that provided a key ingredient for his whiskey: a plentiful source of pure, iron-free water. Since then, one or two things have changed. The grain is brought in by truck these days rather than on mule wagons, and more bottles are turned out in a month than in Daniel's entire lifetime. But the whiskey is still made according to the recipe and procedures that he laid down 132 years ago.
There is a life-size marble statue of the founding father, 5ft 2in tall in his pointy shoes and, in his original office, still preserved in the grounds, "Gentleman Jack" gazes down from a portrait on the wall, stern- faced, with a ferociously bushy moustache, wearing the hat and frock coat that were his customary attire from the age of 16. Despite his straitlaced exterior, Daniel was a gregarious soul. He threw big parties and was said to be fond of female company, although he remained a bachelor and produced no heirs.
He was also known for his fiery temper. In a corner of his office is the safe that, one morning in 1911, he kicked in a fit of fury, unable to remember the combination of the lock. Daniel broke his big toe; gangrene set in, and a few months later he was dead.
His nephew, Lem Motlow, was in charge of the business when Tennessee went dry, several years before national Prohibition. For nearly three decades the distillery lay idle. The state legislature repealed the anti- liquor laws in 1942, but left it to individual counties to make up their own minds.
Thus the sale of alcohol remains outlawed today in most of Tennessee. The state's distilleries recently persuaded the legislature to allow them to sell souvenir bottles to visitors - but the whiskey still cannot be sampled on the premises, only in private homes. They prefer it that way in Moore County, a conservative farming area studded with fundamentalist Baptist churches. Locals in Lynchburg, the county town, call it "the buckle on the Bible Belt".
Roger Brashears' mother is so mortified by her son's choice of job that she never tells anyone what he does for a living, although he has worked at Jack Daniel's for 32 years.
So does no one drink at all around here? "Yes ma'am," says Brashears in his Southern drawl. "It's just that we don't do it in front of each other."
When visiting the distillery, it is advisable to get the terminology right, or you risk some long, hard stares from the folk who work there. Jack Daniel's is not a bourbon; it is a Tennessee "sippin' whiskey", enjoyed for its flavour rather than its intoxicating properties - although many, including Brashears himself, will attest to the latter. "We figure it's OK to drink it," he says, "so long as you don't end up taking a bath in it."
First, travel to the Tennessee capital, Nashville. Unfortunately, American Airlines abandoned its Gatwick-Nashville service as a commercial failure, and so you will have to change planes en route. Discount agents such as Major Travel (0171-485 7017) offer flights to Nashville for pounds 337 on American Airlines, Northwest or Continental Airlines, so long as you travel out and back before late March. From Nashville, the easiest way to cover the80 miles to Lynchburg is in a hired car. All the big rental companies offer good deals if you book ahead.
Who to ask: Tennessee Tourism, Coach House Mews, r/o 99 Bancroft, Hitchin, Herts SG5 1NQ (01462 440784).