Amy Laughinghouse follows the Scotch whisky trail on a lively tour of Scotland.

WHEN Albannach whisky bar in Trafalgar Square introduced a 50-year-old Balvenie for £760 a dram, jaws dropped-and trembling lips sipped. Of course, it’s practically a bargain, when you consider that buys a double.

The cost is certainly a drop in the bucket (or the sherry cask, as the case may be) compared to a selection of whiskies at The Lanesborough’s Library Bar, where a measure of Macallan from 1937 sells for £1,600 alongside another five vintages topping £1,000 a pop.

So what makes whisky quite literally worth its weight in gold? I toured Scotland’s meandering (and sometimes downright wobbly) whisky trail to find out—but it’s best to begin with a dram.

Pour a finger of Scotch, swirl the tumbler, and watch as light plays across the amber fluid like dancing flames encased in glass. Inhale the heady fumes, which may fill your nostrils with the smoky perfume of peat. Finally, take a sip.

Careful now, because this is where whisky really earns its reputation, searing your throat and warming your belly, tracing a course through your body so intense that you would swear it left a mark on your flesh.

Certainly, whisky has made its mark on Scotland, where the inhabitants have been brewing their usquebaugh (Gaelic for “water of life”) since at least 1494. Over the ensuing centuries, this incendiary spirit has become so synonymous with the country that it can legally be called “Scotch” only if it has been distilled and matured in Scotland.

Today, abouty 100 distilleries hunker down amid the misty hills and windswept coast of mainland Scotland and its satellite isles. But you don’t drink in this moody, atmospheric panorama with your eyes alone. Every time you pour a glass of whisky, you taste Scotland itself.

To understand why the surroundings make such a difference, it helps to know how whisky is made, and Dewar’s World of Whisky in Perthshire offers the perfect primer. Start with the centre’s scratch-and-sniff, Willy Wonkaworthy wheel, which features buttons that unleash aromas sometimes found in whisky, for better or worse. (Sweat? Boiled cabbage? Rubber, anyone?) Then visit the adjacent Aberfeldy distillery, where you can see, and smell, virtually every step in the distillation process.

My guide, dressed in a black and green kilt, explained that malt whisky requires only a few ingredients—malted barley, yeast, and water.

First, barley is steeped in water, then dried. If the barley is heated over a peat fire, the whisky will retain a puff of smoke, like a recently extinguished bonfire.

Next, the dried malt is ground in a mill, and the resulting grist is mixed with hot water to produce sugary wort. After the wort cools, yeast is added to induce fermentation. The resulting alcoholic “wash” passes into copper stills, with a portion of the fluid stored in wooden barrels for a minimum of three years before being bottled and distributed.

Most distilleries mature their Scotch in oak barrels from the US that were once used to store bourbon. Some also age their spirit in casks that once held sherry, port or wine, introducing richer, sweeter flavours. If whisky is distilled or matured near the coast, it will likely be infused with the smell and taste of the sea.

Every distillery draws from a particular water source, such as a local spring or a stream, which carries subtle reminders of its journey across the earth, whether burbling up through decaying peat, trickling down hillsides tufted with heather, or meandering past hedges of coconut-scented gorse blossoms.

Given its importance to the whisky’s taste, it’s not surprising that distillers are protective of their water source. Although none, as far as I’ve heard, have resorted to land mines or snipers, Glenmorangie, on the north-eastern coast of Scotland, has fenced its mineral rich Tarlogie Springs and bought 650 surrounding acres to preserve its integrity.

Even that hasn’t always proven sufficient, as Bill Lumsden, head of distilling and whisky creation for Glenmorangie and Ardbeg, discovered when he came across two boys swimming in the spring’s crystal clear waters one day. “That batch,” says Lumsden, “was a bit meaty.”

While you wouldn’t expect to detect “essence of local lads” in your tumbler, some drams do possess a decidedly idiosyncratic appeal.

Robert Hicks, the master blender for Ardmore and Laphroaig, revealed that for years, the marketing slogan for the pungent Laphroaig ten-year-old was “Love it or hate it.”

With its hint of Band-Aid and iodine, it’s perhaps not surprising that this Islay-made whisky was sold as a medicine in the US throughout Prohibition. “It was great for rubbing on your back – but by God, you could still lick it off,” Hicks laughs.

Speyside boasts the country’s largest concentration of distilleries, including The Glenlivet.

Established in 1858, The Glenlivet is set upon 58,000 acres, crisscrossed by old whisky smugglers routes running through pine forests, alongside the River Livet, and across fields where horses and cattle graze.

On the day of my visit, a burly red-haired fellow named Ian Logan demonstrated how those smugglers made their illicit hooch in a 2ft-high, gramophone-shaped still set over an open flame. The clear, heady spirit that dripped out of the copper spigot might have been perfect when paired with Granny Clampet’s squirrel surprise, but I suspected it was best suited to removing fingernail polish... and the lining of my stomach.

Fortunately, “Logan’s Run” bore no resemblance to the six drams of whisky placed before me in The Glenlivet’s sunny tasting room.

As Alan Greig, former director of brand education, led our “tutored nosing”, he twirled each whisky in a short-stemmed flute, then removed a glass disk (which traps the odours) from the opening, and guided the dram beneath his neatly-trimmed white mustache.

“It’s what I call the swirl, slide and sniff,”

Greig says. If you add a few drops of water to each sample, he noted, you’ll discover previously undetected scents, “like walking through a garden of flowers after it rains”.

Finally, after nosing the whisky, Greig encourages us to sample the golden nectar. A Nadurra 16-year-old, which has a strong vanilla flavour and produced a warm burn in my nose and throat, was an early favorite, but it was swiftly supplanted by the increasingly mellow 18 and 21 year olds.

The coup de grace, however, was The Glenlivet 1969, a spectacularly seductive limited release from the distillery’s Cellar Collection.

Aged in a mix of sherry casks and ex-bourbon casks, it was toffee-and-marmalade-infused fluid ambrosia. Only 1,000 bottles were issued, with the sold-out vintage fetching £550 or more per bottle. Given how high the bar has been raised in London, however, perhaps that’s not such a tough act to swallow.

■ More information: Scotch Whisky Association, scotch-whisky.org.uk, tel: 0131- 222-9200. VisitScotland, visitscotland.com, tel: 0845-225-5121. Whisky tasting In London: The Lanesborough, lanesborough.com, tel: 020-7259-5599.

Albannach, albannach.co.uk, 020-7930-0066.