Forget that tired-old coffee ring effect: “Whiskey webs” are the new hotness [arstechnica.com]
A whiskey was successfully matched with its brand 90% of the time in new study.
American whiskeys are distinctive from their Scottish counterparts in one very distinctive way: they leave behind an unusual web-like pattern as droplets dry up, and those webs are different for different brands—making them a kind of "fingerprint." That's a property that can be used not only to tell the difference between brands of American whiskeys but could one day lead to an effective method for the identification of counterfeits, according to a new paper published in ACS Nano.
As we reported last year, [arstechnica.com] Stuart Williams, a professor of mechanical engineering at the University of Louisville in Kentucky, noticed one day that if he diluted a drop of bourbon and let it evaporate under carefully controlled conditions, it formed what he terms a "whiskey web": thin strands that form various lattice-like patterns, akin to networks of blood vessels. Intrigued, he decided to investigate further with different types of whiskey—plus a bottle of Glenlivet Scotch whisky for comparison.
[ . . . . ] In those earlier experiments, Williams tested 66 American whiskeys; only one did not create a web. Whiskey webs appear to be related to alcohol content. Williams and his team had to dilute the whiskeys with water down to about 40-50 percent proof. Specifically, they found that if the alcohol-by-volume level was above 30 percent, there would only be a uniform film; lower than 10 percent, and you get the coffee ring pattern. It's only at an intermediate alcohol-by-volume level of between 20 percent and 25 percent that you get these unique webby structures.
Whether various brands could be detected by taste alone is a subject for further study while self-isolating; provided the principal investigator's spouse does not object.