Whisky traditionalists are a bit like cats—bring water anywhere near them (and their precious neat dram) and they can get pretty mean. Instead of attempting to declaw an anti-water scotch drinker, bring them real evidence that water is actually good for whisky. Science says so.
NPR reports that researchers from the Swedish Linnaeus University used computer simulations to track the exact interaction between molecules of water, alcohol and guaiacol, which provides the characteristic smoky taste and smell in scotch. They found that when the liquid remained at 40 percent alcohol, as you would find in a straight pour of scotch, guaiacol hangs out in the body of the glass. But dilute that liquid with water, and the hydrophobic guaiacol and alcohol molecules move to the surface, releasing the smoky scent up into the air and bringing the scotchy flavor to the front of a sip.