Neat, on the rocks or with a splash of water — whisky can be savoured in a number of ways. How you set up your dram is your own business, but if you’re pouring in the H2O, it does run the risk of getting too diluted and taking away the very essence of the spirit.
Those who prefer to water down their drink a bit do it to take the sting out of the alcohol, which is an acquired taste for many. However, how much water is too much water? Science has the answer.
A 2023 study conducted by five food scientists from Washington State University, Michigan State University and Oregon State University found the right amount of water to put in your whisky before it alters your flavour profile and natural aromas.
Whisky 101: This is the right amount of water to add to your dram, according to science
The perfect ratio… The study, published in the open-access journal Foods, asked a panel of trained whisky connoisseurs to test 25 samples of bourbon, rye, single-malt and blended scotches and Irish whiskies at various dilution levels — 100 per cent whisky, 90 per cent whisky and 10 per cent water, 80 per cent whisky and 20 per cent water, 70 per cent whisky and 30 per cent water, 60 per cent whisky and 40 per cent water, and 50 per cent whisky and 50 per cent water.
As it turned out, the panel decreed that the whisky varieties began to merge at a point starting at 80 per cent whisky and 20 per cent water as the non-hydrophilic molecules were pushed aside and crowded out. Simply put, the 80-20 whisky to water ratio hit the sweet spot, considering that a higher water percentage diluted the distinct flavours of the liquid and made all the different variants taste similar. Fixing up a drink with a water percentage lower than 20 retained its distinct aroma, properties and compositions.
Whisky-water ratio for a double
This means that if you’ve poured yourself a double peg, aka 60 ml of whisky, don’t add more than 12 ml (equivalent to 20 per cent of the whisky’s volume).
Scotch vs bourbon when diluted
The study also found that scotches and bourbons tended to be impacted differently through water dilution. At first, the scotches started with a smokier smell and then, with over-dilution, turned lighter and fruitier. On the other end, bourbons open up with a spicy, rich flavour, which ends up with an aroma of grains and corn, losing the oaky and vanilla traves it carried earlier.
