back to top

This Might Be Why Whisky Tastes Better When You Add Water

It's not just a made-up thing after all.

Posted on

Have you ever seen someone add water to whisky and wonder why on earth they were doing that?

AMC

It turns out there might be a scientific reason why adding water to whisky makes it taste different (or, some would say, better).

And no, it's not just because it waters it down.
Lucentius / Getty Images

And no, it's not just because it waters it down.

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.

Guaiacol is a type of chemical called a phenol, and it's phenols that give whisky – especially very peaty whisky like that distilled on the Scottish island of Islay – its smoky flavour.
Karlsson and Friedman / Via Nature

Guaiacol is a type of chemical called a phenol, and it's phenols that give whisky – especially very peaty whisky like that distilled on the Scottish island of Islay – its smoky flavour.

They found that when the concentration of alcohol is 45% or less, these molecules like to hang out where the liquid meets the air.

So when you take a sip, they're right there waiting for you and your tastebuds."This molecule likes ethanol more than it likes water, so it follows these ethanol molecules to the surface," says Karlsson.
Björn CG Karlsson / Via Nature

So when you take a sip, they're right there waiting for you and your tastebuds.

"This molecule likes ethanol more than it likes water, so it follows these ethanol molecules to the surface," says Karlsson.

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.

Fox

Basically, they're hiding inside the drink and probably won't hit you as hard once you go to take a sip (though the higher level of alcohol might).

Most cask-strength whiskies start out at 60% or more alcohol by volume. When whisky is bottled for sale, it's usually diluted using water to a more palatable 40% alcohol.

"It probably works that the more water you add the more of this molecule you find at the surface, but at the same time you add water you dilute it," says Karlsson, so it's a delicate balance to add enough water to enhance the taste, but not so much to dilute it beyond recognition. "Everyone has his own opinion about how much water should be added to whisky."

Of course, taste and smell are subjective and will vary from person to person.

Columbia

"We each have different receptors that interpret the contribution from a single molecule in different ways, so it's not easy to say, for example, that you should add three drops of water to your whisky and it will taste fantastic," says Karlsson.

He also cautions that it was a very simplistic version of "whisky" used in the simulation. "To be honest it's very naive to say that it's a model of a whisky, because whisky is maybe the most complicated beverage there is in the world chemically. It's composed of hundreds or maybe thousands of organic compounds."

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."

  1. Do you add water to your whisky?

    Do you add water to your whisky?
    Correct
    Incorrect
    Yes, and I can definitely taste the difference.
    Correct
    Incorrect
    Yes, but I don't really notice it tbh.
    Correct
    Incorrect
    No, I tried it once but I didn't like it.
    Correct
    Incorrect
    No, I prefer it neat.
    Correct
    Incorrect
    I don't like whisky, I'm just here for the science.
Oops. Something went wrong. Please try again later
Looks like we are having a problem on the server.
Do you add water to your whisky?
  1.  
    vote votes
    Yes, and I can definitely taste the difference.
  2.  
    vote votes
    Yes, but I don't really notice it tbh.
  3.  
    vote votes
    No, I tried it once but I didn't like it.
  4.  
    vote votes
    No, I prefer it neat.
  5.  
    vote votes
    I don't like whisky, I'm just here for the science.

Kelly Oakes is science editor for BuzzFeed and is based in London.

Contact Kelly Oakes at kelly.oakes@buzzfeed.com.

Got a confidential tip? Submit it here.

Take quizzes and chill with the BuzzFeed app.