And then water comes in like a bomb and destroys that tranquil balance. “When you take a drop of water and put it in a glass of whiskey, you can see all these ripples and all these convection currents. That’s the water you’re adding disrupting that balance,” Hartings says.
Water causes new flavors to emerge from the glass, commonly referred to as “opening up” the whiskey. Hartings explains that the water isn’t adding any new flavors—it’s just water, after all. Nor does it alter the flavor molecules themselves. Instead, water radically rearranges the molecules inside. Hartings explains, “It’s kind of like playing pool. You start off with the racked balls. When they’re sitting in that rack, they’re happy being there. And even when you pull the rack away, they’re going to sit there. But you throw in that cue ball and it disrupts everything. Everything kind of moves around and has to find a new place to be.”
Adding water to whiskey also affects the aroma molecules. “The water and ethanol are like a kid hanging onto a helium balloon [representing molecules that trigger smells]. The kid sees something shiny [water, in this case], and all of a sudden they let their balloon go,” Hartings says. That balloon floats up into your nose and causes you to smell caramel or birch or dried fruit.
Water doesn’t affect all flavors equally, though. Some flavor molecules interact more strongly with water molecules than others. Picture again that kid holding a balloon, now picture him joined by an entire field of kids holding balloons of different colors—some blue, some green, some purple, all representing different flavors and smells. “You put on The Wild Kratts,” Hartings says. “The kids holding purple balloons really love The Wild Kratts. All of a sudden they let go of their balloons, and now you’re smelling more of that purple flavor than others. It’s really about how well those individual flavors interact with water.” The molecules that are attracted to water are less likely to leave the mixture when you add more water, whereas the molecules that are repelled by water are more likely to leave the glass and come to your nose.
While there is some experimentation into the effects of “hard” and “soft” water on beverages like coffee, the area is still fairly new for whiskey research. All Hartings can be sure of is that water quality does, in fact, impact taste by contributing different amounts of magnesium, calcium and carbonate, which help extract flavors in various ways.
With a unique, incredibly complex mix of molecules in every bottle of whiskey, every glass will interact with water differently. If you like to play around with a few drops of water in your whiskey, there’s nearly endless opportunity for experimentation—exactly the kind of scientific research we’re happy to do.