If Your Whisky Tastes Like Mango, There's A Science-Backed Explanation

It's popular for whisky to have flavor notes of vanilla, caramel, toasted oak, or baking spices like cloves or cinnamon. But what about mango? For years, experts have noticed tropical fruit flavors in whisky but didn't know where those flavors came from. Now we do, thanks to a study conducted by the Scotland's Heriot-Watt University in collaboration with the Japanese drink conglomerate, Kirin,and published by the Journal of the American Society of Brewing Chemists.

While certain tasting notes can seem far-fetched, if not completely made up, there is a real scientific reason why those aromas are there. There's a clear link between specific aromas and chemical compounds that are created during the fermentation, distillation, or maturation process of making whisky. For example, ethyl cinnamate is present when there's a note of cinnamon, as is ethyl lactate when there are notes of butter or cream. And the most common tasting note in bourbon, vanilla, comes from a compound found in oak barrels called lignin. 

In the study, Takehiko Hiura, a PhD student at Heriot-Watt, tested 14 whiskies to pinpoint which chemical compounds created tropical fruit flavors. Hiura found that the whiskies with the highest amount of mango aroma contained isobutyraldehyde, isovaleraldehyde, and isovaleraldehyde diethyl acetal. To confirm that these compounds were the source of the mango flavor, Hiura added them to a whisky with a low level of perceived fruit. When they did, the mango flavor in the whisky increased.

The tropical notes found in certain Scottish and Irish whiskies come from volatile compounds called aldehydes and acetals. Aldehydes form during alcoholic fermentation, and when young, they can taste sharp or grassy. But after some time aging, they can react with alcohol and turn into acetals. In the study, Hiura managed to pinpoint the specific acetals that give certain whiskies a mango flavor. 

Dr. Calvin Holmes, who also conrtibuted to the study, says this breakthrough can have a major effect on the whisky industry. "For whisky producers, that's good news: It means they can hopefully dial up or tone down tropical aromas by manipulating existing process steps." Meaning that after this breakthrough, there may be more whiskies with mango notes than ever before. 

Until then, try tasting the difference yourself. In a post under r/Scotch, whisky connoisseurs discussed their favorite whiskies that had notes of mango, recommending the Balvenie Caribbean Rum Cask 14 Year Scotch, RedBreast 21 Year Irish Whiskey, and Glenmorangie 18 Year Highland Single Malt Scotch Whisky. Pour yourself a glass and compare the flavor against one of our recommendations for the smoothest whiskey.