cryptogon.com

Harmless amounts of radioactive carbon have been found in wines made from grapes harvested since the last atmospheric atomic bomb tests were carried out in the 1960s.

But the “bomb pulse” of radioactive carbon lingering in the alcohol of wines produced since could be a good thing for wine dealers and collectors.

Scientists have been able to pinpoint a wine’s vintage to within a year by analysing the levels of radioactive carbon in the wine, a technique they say could help detect fraudulent attempts to repackage cheap plonk as a high-end tipple.

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The wine industry has introduced special seals and labels in an attempt to frustrate fraudsters, but Jones believes analysing a wine’s bomb pulse may give people more confidence that they have not been conned.

Almost all the carbon dioxide in the atmosphere contains the stable carbon-12 form of the element. Each atom of carbon-12 has six neutrons and six protons in its nucleus. But atmospheric atomic bomb tests, which ended in 1963, released vast amounts of radioactive carbon-14 into the air. A carbon-14 atom has two extra neutrons.

When grapes grow on the vine, they absorb carbon dioxide, which contains both stable carbon and traces of radioactive carbon-14 left over from bomb tests, from the air. As time goes by, carbon dioxide emissions from fossil fuel burning dilutes the amount of carbon-14 in the atmosphere.

Speaking at the American Chemical Society annual meeting in San Francisco today, Jones said his team had been able to date wines by measuring the relative amounts of carbon-12 and carbon-14 in the alcohol produced from the grapes.

“The year that the grapes were grown fixes the age or vintage of the wine,” he added.