It’s shortly after 7 a.m. on a Wednesday. Two baristas staff the stainless steel bar of their libation laboratory as the bleary-eyed few shuffle in looking for their dose of the most widely used drug in the nation: coffee.
More specifically, they come for the caffeine that characterizes the bitter but beloved drink. An hour later, the line of devotees will stretch to the entrance of the campus Starbucks, professors and students alike waiting to claim their morning cup of Joe.
A middle-aged man strides in and enthusiastically greets Scott Young, a Starbucks barista. His beverage order is sent to the steamer with barely a word, and he strikes up casual conversation with his baristas, obviously a familiar face on a campus of thousands.
“Coffee? It’s a drug,” Young says bluntly. “That coffee and sugar, keeps you coming back.”
Americans are the leading consumers of coffee in the world, drinking approximately 400 million cups each day. We love the stuff, but what exactly makes up the beverage that greets 54 percent of American adults each day?
The coffee comes from the seed, deceptively referred to as a bean, of the Coffea Arabica plant, from which we get the well-known name “Arabica coffee.” The magic bean’s energizing powers were discovered in Africa and emerged as the drink we enjoy today in Arabia around A.D. 1000 when it became a staple of Islamic life.
The average cup of coffee is 98 percent water. In the remaining 2 percent, diverse chemical compounds affect what we experience in a sip. One of the most dominant compounds affecting coffee’s taste is chlorogenic acid. Responsible for the trademark bitterness of coffee through its breakdown in the roasting process, this acid also lends coffee health benefits as an antioxidant, which protects the body and brain from damaging free radicals. According to the Royal Society of Chemistry, coffee’s acid compounds have been shown to contribute to coffee’s potential to help prevent diseases like Alzheimer’s and type 2 diabetes.
A second prominent compound is, of course, caffeine. The compound responsible for stimulation of the brain and body is part of the group known as alkaloids. Alkaloids by nature have a bitter taste that may serve as a protection mechanism for the plants that produce them. The caffeine we crave is a toxin avoided by many insects and animals. As reported by the Mayo Clinic, however, the average cup of brewed coffee can total from 95 to 200 milligrams of caffeine, well below the 500 milligrams the clinic states could raise concerns for the coffee drinker’s health.
If much of coffee’s flavor compounds make it bitter — and potentially toxic if consumers drink to excess — why is it one of the most popular beverages on the planet?
A third compound in coffee’s complex makeup could provide the answer. Trigonelline, also an alkaloid, contributes the earthy, sweet flavors of coffee as it breaks down and creates new compounds during the coffee’s roasting. The compound has also been shown to contribute to dental health by keeping common cavity-causing bacteria from hanging around on teeth, according to the National Center for Biotechnology Information.
These compounds are just a few of the several hundred comprising the coffee plant, but many of these benefits would be left unlocked without the experts behind the roasting, grinding and brewing.
“Coffee’s got over 700 flavor constituents, so one small thing being off can change the flavor,” said Josh Beard, head barista of local coffee shop K Brew.
Trained by a coffee roaster to recognize the subtleties of the perfect cup of coffee and well-practiced in the daily grind of coffee consumption, Beard operates as both an artist giving life to his passion and a meticulous scientist intent on perfecting a miraculous cure.
“There’s definitely an artistic side to it,” Beard said, “but then also you have to know all the science side of it to make it as good as it can be.”
Many coffee drinkers are familiar with the terms, “light, medium and dark roast.” These terms, Beard said, are on their way out the door for coffee roasters. The primary concern of the roaster is a balanced taste that allows the flavors produced through the heat-generated chemical reactions to emerge to their fullest potential.
“People are getting used to over roasted coffee,” Beard said. “When you over roast it, it can kind of mask some of the flavors you can pull out of it.”
Coffee arrives at K Brew ready for grinding from a rotating base of roasters, offering beans grown in Brazil, Panama, Ethiopia and El Salvador, among many others. Before it reaches the counter of the trendy, rustic wood bar of the north Knoxville café, that coffee is put through a standard taste testing process called “cupping.” By eliminating as many taste-altering variables as possible, coffeehouse staff work to get a handle on the coffee’s natural, perfectly prepared taste, paying attention to the acidity, flavor, body and aftertaste of the bean. This allows baristas to prepare a better, truer-tasting cup of coffee.
Grind size, Beard said, plays a large role in the experience of coffee. If the grind is not fine enough, the flavor components locked in the bean are left unexposed in the brewing, robbing the taster of the coffee’s full potential.
Also influential on the coffee’s taste is the brew method used to get the flavor from machine to mug. K Brew offers myriad options for customers to choose from: the traditional drip method used by coffee-makers found on most kitchen counters; the single-cup pour-over, by which hot water is poured directly over a conical filter full of grounds; the cold drip method, where coffee grounds are steeped in unheated water before the drink is filtered and served; and the chemex, a specifically designed pour-over method that produces a richer, sediment-free cup of coffee.
“There’s always room for improvement in coffee,” Beard said. “It’s just one of those things that you can come in everyday and get better at. It’s a challenge.”
For Young, that challenge began when he joined the team of a Memphis Starbucks at the age of 18. Before his “intense training” as a barista for the most recognizable name in coffee, Young was not a coffee-drinker. Now, Young traces his own love of coffee to a single drink on the Starbucks menu: the caramel macchiato.
“It’s a beautiful drink,” he said fondly. “It’s the first drink I ever tried.”
Hidden behind the bar, the hands of a barista expertly navigate the intricacies of the sugary concoctions rattled off by the customers at the register of the Starbucks inside Hodges library. For the popular lattes, as well as his personal favorite, Young said it all starts with the milk. As it is steamed to frothy perfection, the expert barista will gather syrups and begin preparing a shot of espresso for the hot beverage. Though the contents of a Starbucks cup look like artwork, even the order in which the ingredients enter the cup is handled with scientific precision.
“The shot itself has a certain amount of life before it starts tasting bitter,” Young explained. “So as you incorporate it into your drink you want to do it in that amount of time. Like other coffee shops, a lot of times they’ll let their shot of espresso sit and die, and it’ll taste really bad, just like milk and bad espresso.”
Coffee, whether simply or elaborately dressed, is a part of the morning routine of millions. It is an entry point to the lives of those around us, common ground people around the world stand on. This connection between coffee and society is one Young doesn’t take lightly.
“I like the psychology of it,” Young mused, “because you can either make somebody’s day or ruin it, right at the beginning of their day.”
Young’s friendly customer steps up to retrieve his drink with a smile and a thank you. As he leaves, a young woman takes his place to await her order. Both have chosen to begin their day in the same way, linking themselves to a global network of coffee-drinkers millions strong: a simple sip from a cup full of chemistry.
