We’re caffeine-dependent life-forms. Every morning we stumble out of bed driven by our desire for a daily fix. For the most part, we remain in the dark about what makes coffee taste the way it does. Retail coffee pushes us over the edge with an uppercut of sweetness and spice, but coffee has a unique flavor profile of its own. As coffee is roasted from its green bean form, each stage extracts something new from the bean. Light and dark roast profiles taste different because of the different chemical reactions, aromatics, and acids that are released during the process. The extracted flavor components influence the acidity, aftertaste, and body of the coffee.
As we begin the roasting process, the green beans begin to lose their signature color and turn a shade of yellow. During this stage, there’s a grassy aroma in the air. As the water content within the bean starts to dissipate, the flavors begin to intensify as the appropriately named process of yellowing is carried out.
One of the key reactions for the development of roasted coffee flavor is the Maillard reaction. It’s the interaction of amino acids and sugars that creates a unique flavor. Seared steaks, pan-fried dumplings, cookies, and toasted marshmallows undergo a Maillard reaction too. As the oils migrate outward and the sugars caramelize, the bean turns a shade of brown. During caramelization, a delectable aroma fills the room as some of the volatile compounds reach escape velocity.
The precursor to the light roasted stage is the first crack. Named after the audible cue that makes itself evident once moisture inside the bean evaporates and expands in size. A rift forms within the bean to facilitate an increase in volume. It’s like nature’s alarm that tells you when the bean is just about ready for consumption.
We’ve now created a light roast bean whose flavor is often characterized by crisp acidity, a mellow body, and bright flavors. All of the unique characteristics of the bean haven’t yet been lost. Light roast profiles are beloved for their ability to bring out vibrant flavors and highlight the coffee bean’s origin better than other roast profiles.
Before the second crack happens, we achieve a medium roast bean. This stage stays partially true to the origin while developing new flavors brought on by the roast process. The sweetness from caramelization makes itself apparent thus creating a balanced, well-rounded, and a slightly darker cup of joe. City roasts are soon to follow with less emphasis on the origin and more on the roast.
Taking the roast any further results in developing a dark roast bean. Coffee at this stage has low acidity, a heavy body, and reveals a deeper, darker flavor. While none of the original attributes thrive, they don’t necessarily become bland & bitter. Coffee beans of certain origins do well with dark roast profiles letting them emphasize nutty, chocolatey, and caramel flavors. French roasts are a popular dark roast style. Beans that have been taken much further can only be referred to as bitter black water, although Italian roasts are halted in time to avoid any undesirable characteristics.
Beans are made of volatile & non-volatile compounds. While volatile compounds contribute to the aroma, the flavor is somewhat influenced by the non-volatile compounds since they stay relatively unaffected by the roasting process. Caffeine is the latter. Sweetness & fruity undertones are a consequence of the presence of acids in the bean. Beans of a certain origin have different compositions of various acids and depending on the prevalence of an acid, the bean may be naturally sweet or bitter.
The best way to enjoy a cup of coffee is to bring out the natural flavors of the bean through home coffee roasting. Stopping the roast before origin characteristics get fully eclipsed by the roast attributes should be the way to go. They all have the same amount of caffeine per cup measure. It’s worth experimenting with different roast profiles and origins to understand your coffee preferences. At Bunafr, we specialize in optimizing roasting processes for different beans to extract the best elements and celebrate the unique attributes of each. Our mission is to let you achieve the perfect roast every time to create your ideal cup of coffee.