Headspace test can tell whiskies apart

A quick and simple mass spectroscopy (MS) technique can distinguish between different types of whisky - and identity counterfeits.

The technique – known as headspace MS – was found in a comparative study to be better than other techniques such as near- and mid-infrared (NIR and MIR) and UV-vis spectroscopy in spotting whisky samples from different origins and production processes, including Irish, Spanish, Bourbon, Tennessee Whisky and Scotch.

"Due to the huge variety of whiskies, they are often the subject of adulteration," say the researchers behind the study, which is published in the journal Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy.

While adulteration of whisky is relatively easy to perform, the detection is a big challenge for chemical laboratories. It can occur in several ways, for example by mixing whisky with ethanol originated from a raw spirit or even synthetic ethanol, adding certain ingredients with flavouring properties. Sometimes cheaper whisky is bottled and sold as a more expensive brand.

"It is therefore extremely important to find a quick and simple method to authenticate whisky, not only by its production method and region of production but also by its botanical origin."

They note that headspace-MS acts like an electronic nose, measuring gases in the air above the liquid in the spirit bottle, while NIR and MIR spectrometers act more like electronic tongues because the sample has to be measured in liquid form.

All the technologies under test were able to distinguish between the different whiskies effectively, but the best results were obtained by headspace-MS, which the scientists say "indicates that the biggest differences between different types of whisky are due to their aroma."