You could look that up, along with other scientific truths that render good coffee flavor the elusive thing it is. We are led in large part by our collective nose in the general direction of that steaming mug of aldehydes, ketones, acids, esters, lactones, phenols and pyrroles, among other chemical groups.
Flavor is a melange of smell and taste, and while some of the aroma is experienced at the roof of the mouth, you're not exactly tasting it. As the tongue itself is concerned, much of the coffee experience is always and inevitably fugitive.
Any coffee addict will say, however, it's not necessarily about the taste. While chemists have been studying coffee flavor since the early 19th century, the history of the human encounter with coffee begins not with its taste or even its aroma but with its psychoactive effect.
One legend says it was in Yemen, another says Abyssinia, or present-day Ethiopia. Either way, the story tells how centuries ago a goatherd noticed that his goats were acting funny, that they suddenly seemed agitated. One version even says they were dancing. The goats were not seen in cafes wearing berets and arguing until all hours about literary theory, but they had apparently taken caffeine in berries, which they were spotted chewing from a shrub.
The berry might have been named for Kaffa, where the plant grew wild, or kawah or kahweh, meaning strength in Abyssinia, where the plant was apparently first made into a beverage. It became known as coffee.
Or "coffee," as certain mavens might designate much of the dreadful stuff that goes by the name.
Asked to recall the worst she's ever had, Isabel Fabara hesitates not a moment.
"Hotel coffee" says Fabara, who owns the One World Cafe on University Parkway. "It's horrible. It's like water."
By "hotel coffee" she means the complimentary in-room stuff: the pre-measured grounds in the foil envelope, the little machine there on a side table, the sad brew Fabara describes with an expression of disgust that requires some imagina- tion to spell. Try this: "Eeeeuuuhhhhh."
Charles Houston of Baltimore declines to mention names while enjoying a large decaf and bagel at the Daily Grind in Fells Point, but he says "places where you get coffee with breakfast, I generally find that coffee weak and sometimes bitter."
Jim Lucas of Baltimore recalls a particularly unfortunate brew served on the Pennsylvania Turnpike as a rest-stop freebie.
"It was just brutal," he says, adding a rhetorical question: "What's worse than the stuff at Jiffy Lube?"
On Cold Spring Lane, the coffee shop formerly known as Daily Grind, now called Urban Grounds under new owners, is decorated with an assortment of coffeepots. From booth to booth to display shelves, check out the array of gear in sundry shiny metallics -- percolators mostly.
Anyone remember percolators? The electric kind, say, or the ones you could load up and stick into a campfire? Now you're talking about a brew that can growl and shoo bears.
David Key, who owns Key Coffee Roasters and the Daily Grind shops in Baltimore, suggests that maybe percolators just got a bad name from misuse. He says, "It's not bad as long as you don't let it continue to perk." That forces brewed coffee through grounds that have been exhausted of virtue, shedding -- among other things -- much quinic and caffeic acid.
These respectively bitter and sour elements emerge as chlorogenic-acid splits in heat. Chlorogenic acids are not only unstable, they're also a significant coffee component, found in greater quantities in robustas, the lower-quality beans. Higher-quality arabica beans contain relatively less chlorogenic and more of the fruit acids that give coffee its best flavors.
Grounds for dismissal
The percolator marks a point on the coffee historic trail, as it was largely replaced for home use during the 1970s by the drip machine, chiefly Mr. Coffee, aka "Mr. Never Mind the Taste Just Gimme Caffeine."
The drip machine was more convenient than the percolator, but it had its own brewing problems that contributed to a particularly dark era in American coffee.
If you thought 1970s fashions were regrettable, you should have tried the coffee. By the time the Me Decade arrived, small, local roasters had largely been bought out by multinational corporations in the 1960s, thus cutting community supplies of fresh-roasted coffee.
And, a severe Brazilian frost triggered a sixfold spike in coffee prices in the early 1970s, prompting big coffee producers to market so-called "high-yield" blends supposedly tailored to extract more brew from less ground coffee.
The early home-drip machines were poorly designed in several respects, says Lingle of the Specialty Coffee Association of America. The water spray did not evenly soak the grounds, the temperatures were too low to bring out the best coffee elements early in the brewing and the brewing times were too long, says Lingle.