Serious whiskey drinkers always insist that you get a fuller representation of a drinks flavors by adding a little water, with the help of computer simulations, scientists have confirmed this is indeed true and now know why.
The distinctive taste of whiskey is largely due to a molecule called guaiacol. Guiacol is an amphipathic molecule meaning it has hydrophobic (doesn’t like water) and hydrophilic (likes water) regions. In a study published today in the journal Scientific Reports, researchers simulated what happens to guaiacol when there are different concentrations of water, and which combination makes the molecule most potent.
Whisky enthusiasts will also often add a few drops of water to the spirit before drinking in order to further enhance the taste, but how and why dilution enhances the flavor of whiskey has not been clear. Bjorn Karlsson and Ran Friedman carried out computer simulations of water/ethanol mixtures in the presence of guaiacol to study its interactions. The authors found that guaiacol was preferentially associated with ethanol and, at concentrations of ethanol up to 45%, was more likely to be present at the liquid-air interface rather than in the bulk of the liquid. In a glass of whisky, the authors suggest that guaiacol will therefore be found near the surface of the liquid, where it contributes to both the aroma and flavor of the spirit. At concentrations of alcohol above 59%, the authors found that ethanol interacts more strongly with guaiacol, which means the molecule is driven into the solution away from the surface. The findings suggest that the taste of guaiacol, and similar compounds in whisky, are enhanced when the spirit is diluted prior to bottling and this taste may be more pronounced on further dilution in the glass.
I really love this line from the study:
Overall, there is a fine balance between diluting the whisky to taste and diluting the whisky to waste.
Finally, some real proof that a little water will improve your whiskey drinking taste and aroma profile. No more suffering neat whiskey.