An artificial whisky tongue to rivals the connoisseurs

Unless the whisky has been adulterated with E150 then the colors found in the glass can be used to identify all sorts of whisky characteristics, such as origin, type and age. Something that, so far at least, only the most accomplished whiskey connoisseurs have been able to do so. Scientists have developed a chemical sensor that recognizes whisky’s taste. Long-chain fluorescent molecules help, as the researchers around Uwe Bunz from the University of Heidelberg write in the journal “Chem”. Although real tongues can often clearly distinguish different whiskies, assuming they have enough whisky experience, this has been difficult in the laboratory so far. Although conventional chemical processes can break down whisky into its constituents such as alcohol, vanillin et cetera, most of the flavor carriers can not be distinguished because they are chemically very closely related. The distinction between the complex flavor profiles of whiskeys is now made possible with a sensor plate containing around two dozen different fluorescent molecules. Each reacts to other ingredients. When you add a whisky, the glow of the molecules changes, resulting in a pattern that is unique to each whisky. In principle, our tongue also works this way: when eating or drinking, the taste receptors for sweet, sour, salty, bitter, spicy and umami are activated to different degrees, and from the superimposition of the different impressions, the taste that we perceive arises. The chemists tested their sensor plate with 33 different whiskies: both Bourbons and Scotchs, Blends and single malts as well as those without age and more than 20-year-old treasures. And indeed – the respective whisky characteristics such as origin, type and age were all reflected in typical color patterns. A look at the sensor plate is enough to distinguish a bourbon from a scotch, even if the researchers do not know which components in the whisky react exactly with the color molecules. Nevertheless, the method is suitable, for example, for quality control, to distinguish tainted whiskys from real ones. The Heidelberg working group has already applied the principle to other beverages, such as wines and juices. It could also be used for the control of food in general or drugs and perfumes.