Chemists have trialled a new technique that takes a “chemical fingerprint” of gin in seconds, which could help producers futureproof their gins and conduct quality control.

A team of researchers from Heriot-Watt University worked alongside the University of Edinburgh on the project, and say their findings could help alcohol regulators detect fraudulent products.

The Heriot-Watt team consists of Drs Ruaraidh McIntosh and Dave Ellis and PhD student Kacper Krakowiak.

The trio worked alongside Professor Dusan Uhrin from the University of Edinburgh on the project.

The researchers used nuclear magnetic resonance (NMR) spectroscopy to exam the gin samples. The technique is more commonly associated with finding the structural determination of molecules.

Dr McIntosh said: “Gin production has exploded in Scotland and the UK over the past 20 years, but compared to Scotch whisky it’s very loosely defined and regulated, and not well researched.

“Producers need to know more so that they can ensure they have years of sustainable, flavoursome gin ahead of them.

“And consumers and importers need to know that gin is genuine and the quality they’re expecting.”

Dr Ellis added: “Understanding which compounds are in a gin, and have an impact on flavour and mouth feel, could help distillers improve their gin, or guarantee uniformity of flavour.”

“At the moment, most gin analysis is carried out using mass spectrometry. It’s effective and highly sensitive but does not provide a complete picture of the composition in a single experiment in the way that NMR can.

“NMR basically fingerprints the gin’s chemical compounds. It does this by detecting the signals given by the hydrogen atoms in each compound. These act as markers and enable identification.

“In under five minutes, we end up with an overlay of all these fingerprints, providing a snapshot of the compounds present.”

The team put 16 different gins to the test, some they bought from the supermarket and some samples were provided by colleagues at Heriot-Watt’s International Centre for Brewing and Distilling (ICBD).

Dr Ellis said: “We determined which compounds were present in each gin, and in which quantities.

“NMR can distinguish between different structural forms of individual molecules, and there are many of these cases in gin.

“For example, the flavour compounds pinene and limonene have the same atomic makeup but have different structures and, critically, flavours.

“NMR has huge potential for the gin industry.”

Ryan McDougall
(Australian Associated Press)