Why Whiskey Tastes Better With a Little Water

CNN/Stylemagazine.com Newswire | 8/17/2017, 8:37 a.m.
If anyone has suggested adding a little water to your whiskey, you may want to give it a try. Rather ...
Whiskey samples with Fruit and Cheese Tray

By Ashley Strickland, CNN

(CNN) -- If anyone has suggested adding a little water to your whiskey, you may want to give it a try. Rather than watering it down, the addition may act as a flavor enhancement, and we now know the science behind it, thanks to a new study.

The combination is a bit counterintuitive, which is part of the reason researchers wanted to look at the molecular chemistry behind what's happening in your whiskey glass.

On the surface, whiskey seems simple: It's mostly barley malt and water that goes through a specific process. But from a chemistry standpoint, whiskey includes a complex variety of molecules that contribute to its unique taste. One of those is the compound guaiacol, which lends itself to the smokiness associated with some whiskeys.

Guaiacol is the molecule that two researchers from the Linnaeus University Center for Biomaterials Chemistry in Sweden focused on for their study, published Thursday in the journal Nature.

The researchers looked at both bottled and cask-strength whiskey. Bottled whiskey has been diluted to about 40% alcohol by volume, down from 70% after distilling. Cask whiskey is stronger, at about 55% to 65% alcohol by volume, even if some alcohol evaporates as it matures in barrels for at least three years.

What they discovered is that guaiacol is most present at the surface of diluted whiskey, which is why whiskey with added water tastes better: The taste molecules are at the top of your glass.

"From a molecular perspective, water and alcohol don't completely mix," co-author Ran Friedman wrote in an email. "Instead, we have clusters of water molecules and clusters of alcohol molecules. When whisky is diluted, the alcohol is driven to the surface, and many of the taste molecules follow it because they like to be in a slightly less aqueous environment. The taste that we experience is therefore enhanced -- but there's a limit. If we dilute the whisky too much the concentration of the taste compounds is reduced and the drink will be meager."

In higher-alcohol whiskey, the flavor is different because the taste molecules aren't reacting to the presence of water.

"The most interesting finding was that at high alcohol by volume concentrations -- 59% and up, cask-strength whisky -- the taste compound was surrounded by ethanol molecules in the solution," Friedman wrote.

Friedman and colleague Bjorn Karlsson didn't discover this through taste, although both like whiskey, but by using computer simulations of the molecules.

"They enable us to follow on chemical processes as if we're watching a molecular movie. We usually work on problems that have something to do with biology or human health, but at some point got interested in understanding why dilution affects the taste of whisky," Friedman said.

The researchers believe their findings can be applied to other aged spirits, like brandy, rum and tequila, because they have similar solutions, taste compounds and alcohol by volume.

Though they didn't drink any whiskey during the study, the two researchers enjoy traditional Swedish snaps (what we might call schnapps), ice-cold and undiluted.