Water and Whisky

Scotch whisky is often enjoyed with a couple of drops of water-but does this improve the flavour, or is it simply part of the ritual?

At Devon Drams, our community ranges from seasoned tasters to the whisky curious and I’m in the latter camp. I still remember working behind a Glaswegian bar, staring blankly as regulars reeled off the names of obscure Whisky’s, knowing it would take me at least five minutes to track them down on the miscellaneous Whisky and Bourbon Shelf.

I did, however, learn to pay close attention to how people wanted their whisky served-predominantly because I once gave an older gentleman two small ice cubes when he’d specifically requested one large one, which he did not let me forget…. for months. All of which made me wonder: what does adding water actually do to whisky?

Swedish researcher’s: C. G. Karlsson and Ran Friedman at Linnaeus University in Sweden explored the science behind the tradition. They used a computer simulation to model how ethanol and water behave around guaiacol. (Guaiacol is a compound associated with smoky and bitter notes in Scotch Whiskies.)¹

They found at higher ethanol concentrations (around 59% ABV and above) it stayed in the body of the liquid. But at lower concentrations, guaiacol was more likely to sit at the surface. (which links to the scent and taste) They also found that continued dilution down to roughly 27% ABV increased guaiacol at the surface even further.¹ And that the container affects how the alcohol, guaiacol and water mix together.²

Concluding that adding water to Whisky can improve the taste and experience. However, this might not be generalisable to all whiskeys- although it is certainly relevant to blends which often sit around 27%. Some Whisky drinkers prefer whisky neat- and it may be down to personal preference, perhaps adding a few drops of water might be worth a try- in the name of science. 

Sources: 

1.Karlsson BCG, Friedman R. Dilution of whisky - the molecular perspective. Sci Rep. 2017 Aug 17;7(1):6489. doi: 10.1038/s41598-017-06423-5. Erratum in: Sci Rep. 2018 Nov 1;8(1):16448. doi: 10.1038/s41598-018-34169-1. PMID: 28819215; PMCID: PMC5561096.

2. https://www.newscientist.com/article/2144353-why-adding-a-drop-of-water-can-make-whisky-taste-even-better/#:~:text=Björn%20Karlsson%20and%20Ran%20Friedman,a%20trillion%20frames%20per%20second.