To the enthusiastic connoisseur the oak tint and peaty aroma of a Bunnahabin island single malt sets it a universe apart from the average blended Scotch. But thousands of drinkers unknowingly glug their way through an annual £400m a year of counterfeit whisky.
For years the Scotch whisky industry has been involved in a worldwide battle against criminal gangs to halt the production and sale of inferior products which are passed off as the real thing.
It is estimated that up to 7 per cent of the world trade is counterfeit. In the UK, thousands of pubs and restaurants substitute cheap spirits for genuine Scottish malts and blends.
Until now the authentication process has proved long and cumbersome, with laboratory tests and a two-week wait required to confirm the provenance of a suspect drink.
Yesterday the drinks giant Diageo, which produces 42 million cases of malted and blended whisky a year from 30 distilleries, unveiled the world's first "miniaturised spectroscopic portable testing kit", which can not only tell the difference between real and fake whisky but also the difference between brands.
Each whisky his its own molecular "fingerprint", known as a light-signature, and each of the 10 "authenticators" currently in use by Diageo can store up to 16 of those signatures in its memory at any one time.
By dropping a tiny amount of liquid - about 5 milliltres - into the machine, the hand-held "laboratory in a box" takes about 30 seconds to determine not only if the whisky is genuine but the distillery from which it came.
The rapid results will allow trading standards officers and other enforcement officials to take immediate action against those peddling the poor quality, and often dangerous, imitations.
"The signatures of all of our brands are stored on computer and can be downloaded by officials working in the field, so a suspect drink can be tested against any of our brands at any time," said a spokeswoman for Diageo. "In time we want to roll this out to the rest of the industry because we believe that any counterfeit whisky is bad for the business as a whole and not just Diageo."
Already the device, which was developed at Diageo's brand technical centre in Menstrie, Clackmannanshire, at a cost of just £100,000, has been successfully tested in Colombia, Spain and Venezuela.
With about 90 per cent of Scotch whisky sales being made overseas, where gangs often find it easier to pass off fakes, the "authenticator" could prove invaluable in countries where there is a shortage of ready expertise and analysis.
In South Africa last year, counterfeit whisky, sold under such labels as Original Scotsman and Glen Dowan, was found to contain little more than South African grape and cane spirit with added caramel.
Some would consider it ironic that Diageo is championing the integrity of whisky. The company recently caused consternation among connoisseurs when it turned its Cardhu single malt into a blend of other whiskies, but still insisted on calling it a "pure malt".