See the article here...
"Industry experts claim the market for vintage whiskey has been flooded with fakes that purport to be several hundred years old but instead contain worthless spirit made just a few years ago. Now researchers at the Oxford Radiocarbon Accelerator Unit have developed a method that can pinpoint the date a whiskey was made by detecting traces of radioactive particles created by nuclear bomb tests in the 1950s."
"It is easy to tell if whiskey is fake as if it has been produced since the middle of the twentieth century, it has a very distinctive signature," says Dr. Tom Higham, deputy director of the facility. Nuclear bomb testing in the 1950s saw levels of carbon-14 in the atmosphere rise around the world so the amount of isotope absorbed by living organisms since this time has been artificially elevated."
"Whiskey extracted from antique bottles is sent to the laboratory where scientists burn the liquid and bombard the resulting gas with electrically charged particles so they can measure the carbon-14 in the sample. In one recent case, a bottle of 1856 Macallan Rare Reserve was withdrawn from auction at Christies, where it was expected to sell for up to £20,000, after the scientists found it had actually been produced in 1950. "So far there have probably been more fakes among the samples we've tested than real examples of old whiskey," says Higham.'"
though more about Scotch than Bourbon, kind of interesting I think.