Let's divide the olfactory sense into two distinct categories: aroma and flavor. Aroma, or odor, is the olfactory sensation created by breathing. Strong aromas are present in roasted whole beans or freshly ground coffee, but the prepared beverage itself doesn't release many volatile compounds -- particularly espresso, where the crema acts like a lid. But when we drink coffee, its volatile compounds rapidly evolve in our mouth and travel quickly to the olfactory epithelium in the nasal cavity. Contradictory as it may seem, the sensation is stronger while exhaling.
Smell is not just about aroma. It is also how we experience complex flavors. Surprised? The nose is gateway to a plethora of distinct, natural flavors in coffee, with numbers and types varying by bean variety. Exactly how we experience flavor though smell is little understood. We do know that it involves our brain's attempts to compare the signals inherent in any particular odor to ones it has recorded in the past. That jasmine you smelled in your grandmother's backyard when you were ten? It created a file your brain can access today to recognize the presence of jasmine notes in your coffee.
So what delightful flavors might you smell in good coffee? Among the most prevalent are indeed jasmine, red fruit, berries, nuts, oranges, flowers, chocolate, caramel, and vanilla. The level at which each occurs varies by bean origin and blend composition. If your nose detects the likes of ash, soil, wood, or a rancid or chemical-like flavor, send that cup back. If you prepared it at home, go shopping for fresh beans, and clean your equipment.
The roasting process imbues coffee with roasted or toasted notes, stronger in dark roast than in light. These are delightful, but once again, be afraid of the dark: too dark of a roast, caused by over-roasting, covers numerous desirable flavors present in any good bean.
Are you surprised that a discussion about coffee tasting puts the very sensation of taste dead last? Processing a mere 15 info bits per second, taste brings up the rear in our sensorial speed trials.
A common misperception is that taste recognizes complex flavors. As just explained, that is smell's job. In reality, our taste receptors, located on the tongue, pick up but four basic tastes: sweet, salty, bitter, and acidic. While certain regions of the tongue are more attuned to sensing one taste or another -- salt, for instance, by the center region -- all of our taste buds can perceive all four tastes.
This isn't to say taste doesn't matter. Our first genuinely deep, visceral feedback to coffee's taste comes when cup meets lip. As complex as coffee is, we react very strongly to the presence of these basic tastes, and most commonly state our coffee preferences, and dislikes, in terms of bitterness, acidity, and sweetness. Many of us, myself included, gravitate to an even balance of acidic and bitter, with a touch of natural sweetness. That helps explain the popularity of blends, which let you dial up or dial down characteristics inherent in different beans. Our way at illy is to mix a variety of natural and washed coffees, and then precisely calibrate the roast. As a rule of thumb, lighter roasts are more acidic, while dark roasts are more bitter.
Be a coffee rock star. Experience it with all five senses, and take your pleasure to entirely new places.
Image: Nickolay Khoroshkov/Shutterstock.