Tests conducted by the Environmental Research Center of the Scottish Universities have revealed that 55 bottles of rare whiskeys have counterfeited at least a third of them, the BBC reports. The test was commissioned by Scottish broker Rare Whiskey 101, who is concerned about the "spread of counterfeit whiskey".
They selected their selection of coveted Scotch through auctions, retailers and private collections. After receiving all the whiskeys, the researchers used radio-carbon dating techniques to determine if the alcohol was as old or not as it was marketed. Twenty-one of the bottles were not.
According to Food & Wine Rare Whiskey 101 believes that the 21 counterfeit bottles would still have fallen for some $ 800,000 in some markets. They also believe that there are approximately $ 52 million of so-called rare scotch on the market, which is currently fake.
Co-founder of Rare Whiskey 101, David Robertson told the BBC:
We are firmly convinced that any alleged bottle before 1900 – and in many cases much later – should be considered counterfeit until proven genuine Bottle claims to be a single malt Scotch whiskey. This problem will only increase if prices for rare bottles continue to rise.
This is probably due to the fact that every bottle of pre-1900 malt they tested was not nearly as old as advertised. Two of the most notable examples were a highly esteemed Ardbeg 1885 and a "blended whiskey from Thorne's Heritage early 20th century".
If you want to learn more about the used carbon dating technique, the BBC offers more options detail here.