The subject of whether or not a whiskey drinker should add water to their dram while tasting has been debated time and time again. But one detail within that topic that’s often left undiscussed is how the temperature of that water affects one’s perception of a whiskey’s flavor. While it may seem relatively insignificant, it’s not.
Heat and cold each have a massive impact on how flavors in both food and drink are perceived. Understanding the nuances of temperature as it relates to tasting whiskey is guaranteed to improve your drinking experience, or, at the bare minimum, explain why a whiskey might taste different during the winter versus in the summer, with ice or without.
“A human’s perception of whiskey flavor differs based on a liquid’s temperature, due to how the taste buds perceive flavor at different temperatures,” explains Elizabeth McCall, assistant Master Distiller for Woodford Reserve. “When foods or liquids are cold, the channels in your taste buds do not perceive as much flavor. The reaction to the flavor is enhanced as the food or liquid gets warmer, [and] this is why beer can seem more bitter when it is consumed at room temperature versus when it is cold.”
Rory Glasgow, a single malt Scotch whisky ambassador for the United States and Canada, notes that our taste buds work best when within the range of 59 to 95°F, with their peak detection of flavor at 95°F. “When our taste bud receptors are at 95°F (i.e., close to body temperature) they are wide open and send very clear signals to our brain when flavor molecules land within these conducting channels,” he explains. “Inversely, if the temperature is lowered to 59°F, these conducting channels do not send as clear a signal to our brain allowing us to detect less of that particular flavor. We can see how chilling down your dram can mute flavors as our palate is not at its optimal state for receiving flavor molecules and thus the taste will be somewhat dulled in flavor.”
Given McCall’s and Glasgow’s insights, if you’re a whiskey enthusiast who enjoys teasing apart a whiskey’s flavor profile, then keeping your drink at room temperature or slightly above it is the best way to enjoy the dram’s full spectrum of flavor. When a drink is warmer, you’re more likely to perceive its sweet, bitter and umami characteristics; acidity and dryness are heightened when a drink is cold.
Coldness also has an impact on the appearance of some whiskeys. “To some that are new to whiskey, it can seem unsettling that their whiskey may have all of a sudden taken on a cloudy appearance when water or ice are added, but fear not, this is totally natural in many whiskeys that present themselves as non-chill filtered,” says Glasgow.
Chill filtration has become a point of contention among whiskey aficionados, with many in the camp of being against the refining process. By chill filtering a whiskey, the liquid is carefully refined to remove chemical compounds like fatty acids that often clump together (known as flocculation) at low temperatures, creating a cloudiness in the whiskey. Flocculation typically only occurs in whiskeys under 46% ABV, so non-chill filtered whiskeys under that ABV will become cloudy in appearance if ice is added to them. While the visual appeal of chill filtered whiskeys stands, aficionados don’t like that the refining process also removes compounds that contribute to mouthfeel and flavor. It’s definitely a factor to consider, but by no means should you limit your whiskey drinking to non-chill filtered only bottlings, as both types are different from a flavor perspective.
“I do strongly believe that if you are tasting a whiskey for the first time, it is best to drink it just as the maker presents it in the bottle. So if it is cask strength, drink it first at cask strength, then add your ice or a splash of water to see how the dilution opens up the whiskey and shifts the flavor profile,” says McCall.
The tasting process can vary from person to person, and each time you taste, it’s important to have a full understanding of how the state of your whiskey is impacting your perception of its flavor. “How you enjoy your whisky is a matter best left to the person drinking it,” Glasgow says. “And though I may enjoy my single malt neat, sometimes with a splash of water to open it up if need be, I can concede that my first time visiting Kentucky, coming from Scotland, I was reaching for the ice bucket when enjoying my first bourbon on a hot summer’s evening!”
