Have you ever seen someone add water to whisky and wonder why on earth they were doing that?
It turns out there might be a scientific reason why adding water to whisky makes it taste different (or, some would say, better).
Scientists knew already that when you mix alcohol and water you get a fairly complicated solution.
"If you look on a microscopic level, there are clusters of ethanol in water," Björn Karlsson, an associate professor of physical chemistry at Linnæus University in Sweden and author of the paper, told BuzzFeed News. So he and his coauthor Ran Friedman decided to try to figure out what happens with those clusters when you add in something else.
Their findings are published today in the journal Scientific Reports.
They isolated Guaiacol, one of the molecules that gives some whisky its distinctive smoky taste, and ran a simulation to see what happened to this molecule with different amounts of water and ethanol.
They found that when the concentration of alcohol is 45% or less, these molecules like to hang out where the liquid meets the air.
When the concentration of alcohol is 59% or higher in the simulation, the molecules preferred to mix with the ethanol in the drink and move away from the surface.
Of course, taste and smell are subjective and will vary from person to person.
But there's really only one way to find out what your personal tastes are when it comes to whisky and water.
Karlsson says he isn't much of a whisky drinker himself and he hasn't yet experimented with adding different amounts of water to whisky in real life, but his coauthor bought him a whisky glass when they got their paper accepted. "I've promised him I'll buy a bottle of Scotch, and we'll try to add water to that and see."