Whiskey with two ice cubes

In the 1950’s a popular bar drink was scotch and water served in a high ball glass. It sounds plain and boring but scotch drinkers obviously knew something intuitively about mixing water with scotch.  In 2017, when everything undergoes analysis, scientists can now explain why adding water to your scotch makes it taste better.  Two scientists in Sweden published a paper in Scientific Reports on Thursday August 17,2017 in which the results of their research into the behavior of molecules in a mixture of alcohol and water was examined.  Can you image explaining to a man in a bar in 1950 why adding water to his scotch is better? Probably not, but we examine the scientific reason anyway.

The first step in the process of the investigation by Bjorn Karlsson and Ran Friedman of the Linnaeus University Center for Biomaterials Chemistry was to develop a computer model simulation that strips whiskey down to its most basic elements: water and ethanol. They then looked at how these molecules interact with each other and with guaiacol, an organic compound that the whiskey attains from the wooden barrels during the distillation process.

What the scientists found was that water and alcohol don’t uniformly mix together, and that the alcohol molecules tend to bind to the guaiacol molecules. Next the scientists discovered that at lower alcohol concentrations the taste-creating molecules and the alcohol molecules would cluster at the top of the glass, while with higher alcohol concentrations it would be spread out more evenly throughout the glass.

The conclusions of this research were that water would therefore continue to increase the concentration of guaiacol molecules at the surface, potentially improving the taste. Whiskey drinkers have long said that adding water breaks the surface tension of the drink, allowing more of its aroma to escape. Karlsson says he thinks the team’s research supports that theory, because by adding water, “there will be more ethanol molecules at the interface relative to those found in the bulk. In turn, that will then lead to a lowering of the surface tension.”

After this long drawn out research the conclusion is that long ago when men walked into a bar on the way home from work and ordered a scotch and water in made it the whiskey taste better all the way to the bottom of the glass.  It is easy to replicate this research yourself, walk into a bar, order a shot of whiskey and a whiskey and water and discover which is more pleasing to your palate.