As darkness falls and sideways rain lashes the Land Rover harder and harder, I am struck by a horrible thought.

"Do you think the Shakers were allowed alcohol?" I ask Steve, who's been driving since the morning and is exhausted.

"I don't know, but seeing that one of their central tenets was celibacy, it doesn't seem likely," he answers, trying but failing to keep the worry out of his voice.

Steve and I are on a road trip through America's southern states. We have come to Kentucky to follow the Bourbon Trail from Louisville to Lexington - see the rolling hills of Kentucky and their frolicking horses through the splendour of a glass of the amber stuff, that kind of thing - and thought we would take a small detour to spend a night at the fabled Shaker Village, in Pleasant Hill; a working farm where some of the houses that once served as platonic communes have been turned into upmarket hotel accommodation.

The Shakers are a religious sect that was founded in England, in the mid-1700s, as a spin-off of the Quakers, who were seen as too frivolous. The Shakers (also known as the United Society of Believers in Christ's Second Appearing) or the Shaking Quakers, were so called because they went into a state of ecstasy during worship, shaking more than the Quakers, who merely quaked. Illiterate Manchester cotton factory worker Ann Lee, depressed after the death of all four of her children in infancy, brought herself and the sect to America in 1774. This being during the American revolution, and before Thomas Jefferson, freedom of religion and all that, the Shakers were persecuted and members frequently imprisoned.

Still, through hard work, simple living in communes and trying in every way to emulate Jesus, they prospered through the decades, relying on recruitment rather than procreation to increase their numbers. The Shakers invented the circular saw, the flat broom, the revolving oven and brimstone matches.

And, it turns out, they did make wine. Hopefully, there is some left for Steve and me.

The receptionist shrugs and pulls down the corners of her mouth when we ask if the hotel restaurant is still open.

"There's a McDonald's 15 minutes' drive away," she drawls.

I dive into the souvenir shop next door to avoid punching her, and find a Christmas tree in full bloom (after all, it is late September), a number of beautifully made wooden boxes, exquisitely wrought wooden furniture, brooms and handmade soaps. Those Shakers, denied sex even within matrimony, have spent their time and pent-up energy well.

The building is beautiful in its simplicity: whitewashed stucco walls, gleaming dark wooden floorboards and stark, curtain-less windows.

The diplomatic Steve strides masterfully out of reception: the restaurant is now magically open (too bloody right - it's only 9.15pm) and the rooms cost the equivalent of HK$1,400 a night.

Once the restaurant and waiter have been galvanised into action they carry out their duties to perfection, first of all by bringing us each an Old Fashioned, a bourbon-based cocktail, to set the stage for the Bourbon Trail tomorrow.

When my American friend Kelly introduced me to the wonderful and (probably) healing properties of the Old Fashioned (something that tastes this good has got to be health giving) at Ozone Bar, on the 118th floor of Hong Kong's ICC, I almost cried with joy. Kelly had insisted the waiter make it with Maker's Mark bourbon, and to see this famous distillery and taste its produce, Steve and I took a two-hour detour earlier in the evening only to find a sad and lonely laminated sign saying "bourbon tours finish at 4.30pm".

But with an Old Fashioned in hand and Shaker Village's fantastic tomato soup inside me everything looks so good that I only grind my teeth perfunctorily when I discover there's no Wi-fi in the room. Bourbon soothes all nerves.

And it doesn't hurt that the Old Fashioned is the favourite drink of one Don Draper, from a certain show called Mad Men. If that series is anything to go by, in 1960s America people were so busy knocking back bourbon and its distant, watered-down cousin, Canadian Club Whisky, they hardly had time to work.

In reality, the 60s saw a near-fatal decline in bourbon consumption, possibly because it was seen as the drink of toothless hillbillies, or perhaps it just didn't taste very good. The fierce, dark, serious real man's drink was elbowed out by frivolous vodka-based concoctions with colourful umbrellas hanging jauntily from glass rims.

It wasn't until the 80s that bourbon started to claw its way back into the market, thanks to younger drinkers in Japan; their taste for aged, single-barrel spirits such as Maker's Mark and the wonderfully named Knob Creek saved the brands and their distilleries from sinking into oblivion. But the youth of Europe and America still weren't keen.

By 2012, though, the ultra-suave Draper had begun to work his magic. The bourbon distilleries of Kentucky, despite admitting that some of the finest brown liquid is now made in Japan, have since started producing at full speed - if you can talk about "speed" in a process that takes up to 23 years.

THE NEXT MORNING it's still raining and the famous rolling hills are obscured by fog. We swing by a Shaker workshop, where "Cooper" used to work. Cooper? An American film star? No, I learn from the guy making brooms: the surname Cooper means "barrel-maker", or rather, as he testily informs us, "cask maker". Because a barrel is a measure of grain, not a receptacle; damn tourists!

Wow! Two pieces of new information in less than a minute; this trip is proving to be edifying.

It's a miserable morning, but my mind is filled with sweet memories from the night before.

So, what is bourbon's secret? And what is the difference between whisky and bourbon? Kentucky, origin of 95 per cent of the noble drink, should give me the answers.

The guys at the Buffalo Trace Distillery, about an hour's drive from Shaker Village, don't mess around. The drinking tours start at 9.30am and take an hour, the affable guide, another Don, tells us. Being cautious, we choose the one starting at 11am, because we have to drive to western Pennsylvania afterwards.

The tour kicks off in front of an old medicinal-looking glass cabinet full of bourbon bottles with interesting-looking labels. "Medicinal" isn't far off the mark; during the dry, dark years of Prohibition, that's what bourbon became.

When Prohibition became federal law, in 1920, lawmakers congratulated themselves on having rid America of the scourge of alcohol once and for all. Now there would be no violence and no crime.

But wait! What would members of Congress and other powerful men drink while kicking back with golfing pals after a hard day of lawmaking? Oh dear.

They quickly found (or came up with?) a loophole in the law: alcohol could still be consumed and it could still be produced legally if it were for medicinal purposes. A staggering number of people suddenly developed a slight cough and mysterious headache. Bourbon (100 proof), it turned out, could treat any ailment, and three bottles of it were allocated to each patient per cough-riddled month.

Buffalo Trace was one of only four distilleries in Kentucky that was allowed to stay open during Prohibition and it has been producing bourbon and whisky continually for 200 years.

The lawmakers, as well as having shot themselves in the foot in terms of the Old Fashioneds and whiskey sours, realised they had effectively cut two thirds off the federal revenue; money that swiftly found itself in the pockets of Al Capone and other gangsters. Ouch! But the fact that Prohibition coincided with the Great Depression is probably just a coincidence.

Despite the persistent rain, and the distillery being mostly hidden behind tour members' umbrellas, it's still easy to appreciate the grandeur of Buffalo Trace, with its majestic brick buildings, inside which the bourbon "sleeps" in maturing rooms, waiting to be bottled.

The maturing process, during which the corn spirits react with other ingredients, such as barley and honey, is everything. It takes a minimum of three years, but veteran tipple Pappy Van Winkle is left to mature for up to 23.

"The change in taste happens in the barrel, not the bottle," Don tells us sternly, as if anyone had been arguing this point.

Steve and I exchange glances, for we now know what a barrel is. But we say nothing. And anyway, Mr Cooper, language changes and "barrel" is now the accepted term for a "receptacle holding dry or liquid products".

In the case of Buffalo Trace, a barrel is made of 32 staves of white oak using no nails, screws or glue, and the inside is burnt sterile. The charred oak gives the bourbon its distinctive flavour.

Don gets us out of the rain and into one of the maturing houses, where row after endless row of barrels await the bottling of their contents. At any given moment there are 300,000 barrels, each containing 53 gallons of bourbon, in Buffalo Trace, the "most award-winning distillery in the world".

However, only half, or even less, of that bourbon will see the inside of a bottle. Natural evaporation through the oak, known as "the angels' share", will brutally reduce the contents of each barrel until as little as three to four gallons remain, as is the case with old-timer Pappy.

We've reached the one-hour mark and the group is becoming restless: when does the chugging start? Don must sense this, because he deftly manoeuvres us into the bottling and packaging plant, where about 15 workers are filling bottles with bourbon, stuffing a stopper in the shape of a galloping horse and rider into their necks, putting the bottles in boxes and labelling them with all the relevant information for bourbon buffs, and government inspectors.

At almost 1pm, we're still not drinking. Come on, Don! Stop talking about the change happening only in the barrel (not in the bottle, as with wine, you see) and show us the drinks!

The others seem to be seasoned Bourbon Trail travellers. They have all the time in the world and are planning on visiting other distilleries before the day is over. But even they seem to give a huge sigh of relief when Don says, "Let's go and taste some bourbon!"

In the tastefully decorated bar above the souvenir shop, Don starts lining up the bottles. Finally! I see to my relief that, unlike with wine tasting, there will be no spitting out of the valuable drops here. Steve and I look at our watches while Don puts off the drinking with many anecdotes and much arranging of glasses. Come ON!

My anxiety disappears as soon as the full force of the distillery's flagship tipple, Buffalo Trace Kentucky Straight Bourbon Whiskey, hits my tongue, the taste shooting straight to my brain and telling it to go and sit on a porch in a gleaming mahogany rocking chair while horses frolic in the paddock kicking up autumn leaves in the golden sunset of the Kentucky autumn.

It's like all the very best chocolates from your childhood rolled into one and spiked with a generous amount of adult.

When you go bourbon tasting in Kentucky, don't be in a hurry. Take three days. These guys don't rush things; they don't have to be two states away by nightfall and neither should you.

So what is the difference between bourbon and whisky (sorry, I mean, whiskEy to put it Americanely)? The former is made from corn and the latter from grain, and the former tastes great and the latter not so great. But bourbon is called "bourbon whiskey" so … who knows?

And by this stage, who cares? And anyway, Steve is driving.