We've all encountered that whiskey snob who insists on adding a couple of drops of distilled water to "open up" and enhance the flavor of their amber restorative. But, as in most cases of alcohol snobbery, no one really knows why diluting whiskey supposedly makes it taste better—until now, that is.
For all of the grains-and-barrel alchemy of whiskey-making, there is, of course, a more scientific chemical reason why whiskey tastes the way it does—whether it's from Scotland or Kentucky—and that reason is a molecule called guaiacol.
According to a recent study published in Scientific Reports, understanding guaiacol's interaction with water is the key to unlocking the secrets of whiskey-water ratio optimization. Using computer simulations, authors Björn C. G. Karlsson and Ran Friedman were able to measure how guaiacol is affected by different concentrations of water.
Turns out that at alcohol concentrations of 45 percent and lower, the guaiacol molecules in whiskey come to the top of the glass, making it smell and taste better, whereas at 59 percent ABV (alcohol by volume), guaiacol gets dispersed throughout the glass, away from the surface, and thus away from the nose and mouth of the drinker.
Distillers already know this to a certain extent; whiskey is typically distilled at 70 percent, and then diluted with water to somewhere around 40 percent; then, it's further diluted by drinkers with ice, water, soda, or whatever else they want.
But this computer modeling isn't just conversational fodder for the next time you're geeking out over whiskey—there are could be some pretty practical implications for the spirits industry.
"This indicates that the taste of guaiacol in the whisky would be enhanced upon dilution prior to bottling," the authors stated. "Our findings may apply to other flavor-giving amphipathic molecules and could contribute to optimizing the production of spirits for desired tastes."
So, next time you're drinking, pour one out for Björn C. G. Karlsson and Ran Friedman, whose computer modeling helps us better understand the magic of whiskey. Or, better yet, pour a little water in your bourbon—but only if it's above 45 percent ABV. Hey, science is cool.