The Scottish have decided to take back the pride of whiskey, developing an artificial “tongue” which can taste subtle differences between drams of the drink, which they are hoping will cut down on the trade in counterfeit versions. The research, which was conducted by engineers and chemists from the Universities of Glasgow and Strathclyde, was supported by funding from the Leverhulme Trust, the Engineering and Physical Sciences Research Council, and the Biotechnology and Biological Sciences Research Council, and was published in the Royal Society of Chemistry’s journal Nanoscale.
The tiny taster uses sub-microscopic slices of gold and aluminium, arranged in a checkerboard pattern, which act as the “tastebuds” of the artificial tongue. The researchers poured samples of whisky over the tastebuds – which are about 500 times smaller than their human equivalents – and measured how they absorb light while submerged.
Statistical analysis of the plasmonic resonance, or how the light was absorbed by the metals, allowed the team to identify different types of whiskies. The “tongue” was able to taste the differences between samples of whiskies from Glenfiddich, Glen Marnoch and Laphroaig with greater than 99% accuracy. It was capable of picking up on the subtler distinctions between the same whiskey aged in different barrels, and could tell the difference between the same whiskey aged for 12, 15 and 18 years.
Dr Alasdair Clark, of the University of Glasgow’s School of Engineering and the paper’s lead author, says that the artificial tongue could easily be used to “taste” virtually any liquid, which means it could be used for a wide variety of applications, including food safety testing and quality control. The technology can also be used to monitor rivers for environmental hazards and identify contaminated liquids.
At the moment, there are a number of other techniques for analysing liquids, with the most common being the analysis of the weights of the constituent molecules. Another synthetic tongue developed in 2017 uses 22 different fluorescent dyes and analyses how they affect a liquid’s brightness.
“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,” Clark said in an interview.
“You could train your particular ‘tongue’ to know what one of these whiskies ‘tasted’ like, so that when the fake stuff came along it could identify it and when the real stuff came along it could confirm that it was the real stuff.”
While this seems a good solution to fight counterfeit whiskey sales – it is estimated that around $52 million worth of high-end counterfeits are circulating in the world today – the “tongue” hasn’t found universal acclaim. Charles MacLean, a Master of the Quaich, the whiskey industry's highest accolade, has gone on the record saying that whiskey blenders and quality assessors rely entirely on smell.
“Our sense of taste is crude in comparison. While we have ... around 9 000 taste buds, we are equipped with between 50 and 100 million olfactory receptors and can detect aromas in minuscule amounts, commonly in parts per million, sometimes parts per billion and with some chemicals parts per trillion. Will this ‘tongue’ be as sensitive as this, I wonder?” he asks.