After a quality bean has been carefully chosen, dried and processed (becoming a dense, green bean), the bean must then undergo the roasting process. The roasting process is one of the most key and integral stages of developing and highlighting a bean’s unique flavor profile.
The roasting process involves a complex series of transformations that the coffee bean undergoes, which are often described through the following stages below.
Stages of Roasting
Yellow: For the first few minutes the bean remains greenish, then turns a lighter yellowish emitting a distinct grassy smell.
Cinnamon: The beans start to steam as the internal moisture content dissipates.
First Crack: Soon you will hear first crack, a distinct cracking sound. Sugars start to caramelize, moisture begins to escape, the structure of the bean breaks down and internal oils begin making the course outward.
City Roast: After first crack, the roast can be considered complete any time according to the roasters preference. The cracking is a reference, along with sight and smell, indicating to the roaster what point of the roasting cycle it is. There is a fine line to walk at this stage. It could be the difference of a sour underdeveloped roast or a complex flavorful cup.
City + Roast: Caramelization continues, oils begin to course more outward, and the beans expand more in size. The complexity and aroma of the coffee has reached its pinnacle at this stage.
Second Crack/Full City: At this point a second crack can be heard, often more volatile than the first. Again a very fine line to toe at this stage. Stellar for a balanced espresso, with subtle fruit and chocolate notes. The roast character begins to muffle the origins unique characteristics. Distinct caramelized roasty tones are typically detected along with sweet or bitter chocolate notes if taken a second too far.
Full City +: A few more pops into second crack. Roasting all the way through second crack will typically result in overdevelopment of the roast. As the roast becomes very dark, the smoke becomes pungent as sugars burn completely, and the bean structure breaks down. As the end of second crack approaches, this is better referred to as a French roast.