Scientists from Scotland’s University of St Andrews have developed a new technique to accurately measure the authenticity of whiskies.
This could come useful when authenticating some of the world’s most exclusive whiskies – iconic bottles of whisky have been known to sell for prices over $1.3 million – without ever removing the cap.
According to a 2018 study published by the European Union’s Intellectual Property Office, counterfeit drinks cost the UK economy more than $257 million in lost revenue each year.
The St Andrews method uses lasers which can see through the bottle to analyse the contents.
The challenge however in doing so was to record a signal from the contents without recording signals from the glass.
The team led by professor Kishan Dholakia managed to overcome this by using laser spectroscopy, a process which shines laser light into a substance of interest and the sample scatters the light into different colors.
The precise colors of the scattered light depend on the chemical make-up of the substance and can therefore be used to identify materials ranging from bacteria, food and drink, through to the paint on sculptures and explosive powders.
The scientists had nearly a decade ago demonstrated that laser spectroscopy could be used to identify counterfeit whisky.
However, their previous method was hampered by the fact that the alcohol is not the only material to scatter light: the glass of the bottle can create an even bigger signal which dwarfs the signal produced by the contents.
Therefore, previous setups required the removal of a small quantity of the liquid for testing.
Now Dholakia’s team consisting of Holly Fleming, Mingzhou Chen and Graham Bruce, have used a glass element to shape the light to produce a ring of laser light on the bottle surface and a tightly focussed spot within the liquid contents.
As the signal from the bottle and the signal from the liquid are at different positions, a detector can be placed to record only the signal from the liquid, meaning the bottle contents can be assessed without ever opening the bottle.
According to Dholakia, the new approach does not require complex optical setups and therefore promises to be easily manufactured for widespread use.
Moreover, this method isn’t just limited to whisky; it can also be used to authenticate vodka and gin.
Image and content:Pexels/University of St Andrews