Part I: How the Roast affects the Coffee’s Flavor
Before we knew much about coffee, we’d buy black beans glistening with oil, with descriptions like, dark roast, smoky, robust flavor. This sounded pretty good because, who wants to drink a whimpy cup, right? If dark roast meant robust flavor, then it would stand to reason that a medium roast or light roast must somehow be less flavorful. Once we started learning how to roast and cup coffee however, we learned that nothing could be farther from the truth!
Simplistic comparisons have been made between roasting coffee and barbequing meat, in terms of how one’s “cooking technique” ultimately affects flavor development. In both cases, there’s a search for the perfect time/temperature relationship to create a wonderful end result. Add too much heat and/or time and the end product tastes like any burnt barbequed meat or burnt roasted coffee, instead of like the sought-after savory cut or the deliciously complex cup of coffee.
Coffees from around the world contain unique flavors trapped inside them, and it’s the roaster’s job to coax them out through the roasting process. If he or she is not paying close attention to the beans throughout the roasting process, making adjustments as needed to the heat and time, then certain flavors will not develop or will possibly be roasted out of the bean. Knowing that there are many factors such as density, size, age, and moisture content that affect how a bean roasts, a roaster will roast several batches and cup each batch to determine how to best roast each type of coffee.
Come to our public coffee cuppings, and you’ll be able to taste coffees side by side. (Cuppings are usually the third Sunday of the month at 1:30pm — get details at our website and in this newsletter.) This is where the sensory adventure begins! You will discover personal preferences, likes and dislikes, and you will begin to taste hints of citrus, fruits, wines, chocolate, spices and possibly flowers. Then, you will truly appreciate how a skilled roaster took meticulous time and care to bring those flavors out instead of roast them away. You will also notice that all of our beans are brown and oil free, not black and shiny, an indicator that the coffee was carefully roasted to bring out its individual flavor profile.
Part II: Coffee Roasting Crash Course – What a Roaster Looks, Listens and Smells for When Roasting Coffee
Techniques used for roasting coffee vary depending on the type of machinery, accompanying technology and roasting ideology/philosophy. Regardless of technique, coffee goes through a number of transformations to take it from a dense, green/grey bean to a light, puffy, brown/black, deliciously aromatic gem.
Using one’s senses, the following may be observed during the beans’ metamorphosis:
I. Greenish/grey beans enter the roaster.
II. Beans heat up and change color from green, to chartreusey yellow to light brown. They smell grassy as they release moisture. One later observes steam leaving the roaster that smells like bread.
III. The roaster listens for a light popping sound (1st crack), an indication that the roasting process is in full swing. Sugars inside the beans are carmelizing, flavors are developing. Steam is turning to oily smoke.
IV. Between 1st crack and 2nd crack (a sizzling sound heard close to the end of the roasting process) one feverishly checks the color and internal temperature of the beans. This is where roasting skills really matter. Intense observation helps the roaster nudge the flavor development along through tiny heat and airflow adjustments.
V. Because the beans become exothermic (creating their own heat), once they have reached their optimum roast, they are quickly dropped from the roaster into a round cooling tray that moves them and flows cool air around them. The timing of this move is critical to prevent the beans from being roasted too darkly or being burnt.
VI. You might be surprised to find that the beans will smell grassy, bready, smoky smells during the roasting process. The lovely, intoxicating coffee aroma comes later as the beans are cool and off-gassing carbon dioxide.