Teams from two Glasgow universities have built a tiny taster that exploits the properties of gold and aluminium to test differences between the spirits.
Sub-microscopic slices of the two metals, arranged in a chequerboard pattern, act as the ‘tastebuds’ in the team’s artificial tongue. The researchers then poured samples of whisky over the tastebuds and measured how they absorb light while submerged.
Statistical analysis of the very subtle differences in how the metals in the artificial tongue absorb light – known as plasmonic resonance – allowed the team to identify different types of whiskies.
Sampling a selection of whiskies from brands such as Glenfiddich, Glen Marnoch and Laphroaig, the tongue was able to taste the differences between the drinks with more than 99 per cent accuracy.
Furthermore, the tongue was capable of picking up on the subtler distinctions between the same whisky aged in different barrels and tell the difference between the same whisky aged for 12, 15 and 18 years.
“We call this an artificial tongue because it acts similarly to a human tongue – like us, it can’t identify the individual chemicals which make coffee taste different to apple juice, but it can easily tell the difference between these complex chemical mixtures,” said Dr Alasdair Clark of the University of Glasgow’s School of Engineering.
“We’re not the first researchers to make an artificial tongue, but we’re the first to make a single artificial tongue that uses two different types of nanoscale metal ‘tastebuds’, which provides more information about the ‘taste’ of each sample and allows a faster and more accurate response.
“While we’ve focused on whisky in this experiment, the artificial tongue could easily be used to ‘taste’ virtually any liquid, which means it could be used for a wide variety of applications.”
Clark added: “In addition to its obvious potential for use in identifying counterfeit alcohols, it could be used in food safety testing, quality control, security – really any area where a portable, reusable method of tasting would be useful.”
The paper, titled ‘Whisky tasting using a bimetallic nanoplasmonic tongue’, is published in Nanoscale. The research was conducted by engineers and chemists from the universities of Glasgow and Strathclyde.