Last time on Coffee Flavors Deconstructed, we talked about coffee flavors and how geography affects a coffee's flavor. This time, we consider the “how” of coffee flavor, the things that can be done to the green coffee bean that affects the flavor in your cup.
There's a reason people have historically roasted coffee beans, ground and brewed them. Green coffee tastes grassy and bland. The beans have a waxy texture that's not particularly pleasant. Ethiopian goats may enjoy raw coffee beans, but people prefer their coffee roasted and brewed.
You decide how to brew your coffee. If you have any questions, we have some handy tips on our FAQ page. This blog post focuses on the roaster's role in coffee flavor, how roast level affects the flavor of your beans.
Coffee has more flavor compounds than any other beverage people consume. The temperature and speed of roasting green coffee strongly affects the development of the flavor compounds. Coffee flavors need time to develop. If a roaster heats the beans too quickly, the sweet, complex flavors won't develop properly, leaving a coffee that tastes thin and sour.
Too much heat kills coffee flavors. Once coffee beans reach the right temperature, they need to cool off...fast. That's because the coffee has reached a point where the roasting is an exothermic reaction. It produces heat and keeps cooking the beans, even if the roaster is off. Left alone, these beans will darken, blacken and sometimes even flame. The desirable flavors are burned away, leaving only smokey and charred flavors.
High-grown coffee produces dense beans that take dark roasts well. Some beans, though, will burn at darker roast levels, even if the beans are cooled properly. Lower grown coffee produces softer, more delicate beans that will burn if heated too high. A good example of a wonderful but delicate coffee is Kona Pahala. The moderate altitude produces beans with excellent flavor that turn into char if heated too high or too long.
Even if the beans are roasted perfectly, heated to an optimal temperature for a given roast level and cooled quickly, the flavor of the brewed cup will change, depending on the roast level. Bright and lively notes, like floral, citrus or berry, and each coffees' distinct varietal character develop first (at 410° F-430° F). As a result, they are most pronounced at a Cinnamon through Full City roast level. The body of the coffee, on the other hand, really starts developing at a City roast level (420° F) and remains high through the espresso roast levels (450° F and 460° F). Sweetness, like body, develops as the beans get hotter, so the sweetest beans are roasted to a Vienna roast level or darker (440° F-460° F). Higher temperatures transforms lively notes, turning them sweet. A high-grown coffee that is both sweet and lively, like Organic Peru La Florida, loses its brightness, but grows sweeter and bolder as it gets darker.
One of the challenges of roasting coffee is choosing the right roast level to bring out the best in each coffee. That's why we offer a “Roaster's Choice” option. One example: let's go back to Organic Peru La Florida. Since we love the balance of creamy body with sweet and lively richness that the Peru achieves at a City roast level, we chose City Roast for Roaster's Choice. Another way to optimize flavor, particularly with blends, is to roast the beans at different roast levels. By roasting lively beans lighter and sweeter, heavier-bodied beans darker, the roaster can produce the best of both in a single cup of coffee. Our ReNew Roast (Roast Pair: Foglifter option) is a great example of the power of mixing roast levels.
People have different tastes and preferences. We chose a lighter roast for the Organic Peru, but it's great at darker roast levels, too. Many of our customers prefer it dark, and it's one of the best choices for a French roast level. That's why we let you choose the roast level of your coffee. You get to decide what flavors are important to you.
For an even quicker summary of how roasting affects the flavor in your cup, check out our Coffee Flavors Deconstructed page. For those of you who enjoy charts, we have a more detailed roast level chart on our FAQ page.
Thanks for reading Coffee by the Blog!
~ Carrie, Paul and the Coffee geeks at Coffee by the Roast