Whisky connoisseurs have long claimed that whisky tastes better with a splash of water, or on the rocks with ice cubes. And while that will always, ultimately, be a matter of taste, scientists in Sweden have decided to study how the addition of water chemically alters the drink. They report in the journal Scientific Reports that they think they've hit upon a clue: diluting whisky with water coaxes the fixed number of taste molecules to the drink's surface, where we can enjoy them infiltrating our nostrils and mouths.
To test this, scientists made their own computer model simulations to observe the water and ethanol of whisky and then watch how the molecules of those basic elements interact across different concentrations of the molecule guaiacol, which gives single-malt Scotch whisky a smoky taste, reports NPR. It turns out that when whisky is above 50% alcohol, guaiacol lays low, resting at the bottom of a glass. A little water moves it closer to the surface for a boost in flavor, breaking dense clusters of alcohol, which cling to guaiacol molecules, and dispersing them upward. So what level of dilution is best? Popular Science asked Wild Turkey's master distiller for his thoughts; he admits to adding two ice cubes. (Scotch whisky sales recently took a dive in the US.)