More than a third of vintage Scotch whiskeys tested at a specialist laboratory has been found to be fake, BBC Scotland has learned. Twenty-one out of 55 bottles of rare Scotch were deemed to be outright fakes or whiskeys not distilled in the year declared.
The tests were conducted at the East Kilbride-based Scottish Universities Environmental Research Centre (SUERC). It used advanced radiocarbon dating techniques to reach its conclusions.
SUERC measured residual concentrations of a radioactive isotope of carbon present in the alcohol contained in each bottle in order to establish the ages of the whiskeys.
The samples had been sent for analysis by whiskey broker Rare Whisky 101 (RW101), which said it was responding to growing concern surrounding the proliferation of fake whiskey in the secondary market.
The bottles had been selected at random from auctions, private collections, and retailers.
Last year, the same company exposed a £7,600 dram of vintage Scotch bought in a Swiss hotel as a fake.
The rare whiskey bottles identified as fakes this year included an Ardbeg 1885, which had been acquired from a private owner, and a Thorne's Heritage early 20th Century blended whiskey purchased from an auctioneer.
RW101 said a total of 10 single malts purporting to be from 1900 or earlier were found not to be genuine. The company said that if tests had proven all 21 bottles to be genuine, collectively they could have been valued at about £635,000.
RW101 has estimated that about £41m worth of rare whiskey which is currently circulating in the secondary market - and present in existing collections - is fake. That is more than the entire UK whiskey auction market, which RW101 has forecast will exceed £36m by the end of this year.
RW101 co-founder David Robertson said, the vast majority of vendors were not knowingly selling fake Scotch but every purported rare whiskey bottle should be assumed to be fake until proven genuine, especially if it claimed to be a single malt.
He added: This problem will only grow as prices for rare bottles continue to increase.
The exploding demand for rare whiskey is inevitably attracting rogue elements to the sector.”