Describe Your Coffee With Science

There’s an art—and a lot of science—to a consistent cup of coffee

SCAA Flavor Wheel
A new flavor wheel groups together different flavor attributes of coffee. SCAA

Is that a tobbaco-like note in your coffee? Or perhaps it tastes a bit like malt, peapods, acetic acid or molasses. No matter what your coffee tastes like, that flavor was imparted by a coffee roaster and verified by a taster—and now, roasters have teamed with sensory scientists to create an updated way to characterize how coffee tastes.

It’s called the Coffee Taster’s Flavor Wheel, and it’s the brainchild of coffee researchers and the Specialty Coffee Association of America, which announced the new wheel this week. The wheel is similar to the aroma wheels used by oenophiles to describe the fragrances of wine. Like wine, coffee beans reflect a particular “terroir,” or aspects of growing climate, and the ways in which they are roasted can bring out different flavor profiles ranging from bitter to sweet. (This video explains how coffee tasters use “cupping” to taste different roasts.)

More science went into the updated wheel than you might think. Sensory scientists at Kansas State University created something called the World Coffee Research Sensory Lexicon, a kind of dictionary of the many different attributes of a cup of joe. Each flavor is tied to an actual object so that roasters can describe both a type of flavor and its intensity when they talk coffee. The lexicon was used as the basis of a kind of lingua franca among tasters—a language that lets roasters ensure they’re talking about the same thing when they discuss the different notes they detect in a particular brew.

Once the language was established, researchers from the University of California, Davis undertook the even heavier task of figuring out how coffee tasters group all of those flavors together. A study of over 70 tasters showed that these sensory specialists were pretty consistent in their groupings.

Coffee is gaining steam in academia. But is the sensory science behind things like the lexicon and flavor wheel really legit? The field doesn't just slap scientific terminology on subjective tastes. Rather, this emerging field brings food science together with disciplines like computer science, psychology and neuroscience. Sensory scientists help dictate what consumers eat (they’re the ones responsible for tweaking the delicious blend of fat, sugar and salt that keeps you chomping on things like chips).

Sure, there’s a subjective aspect to the senses, and how people report what they see, taste, feel, smell and hear is often influenced by factors like culture and memory. But the more that researchers turn their attention toward the ways in which groups of people report and categorize those sensory experiences, the better sense scientists can make of them.

So next time you grab a cup of coffee, pause after you sip and think about whether you taste something sour, floral, fermented or pungent. After all, the cup you enjoy will likely benefit from research like the new flavor wheel—and you’ll get an even richer experience out of the bargain.

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