Roasting coffee is the process of chemical reactions occurring to bring a raw coffee cherry seed to the brown coffee “bean” most people would recognize. Coffee has been around since about the 16th century, and although it’s birthplace is considered to be Ethiopia, there are reports of it being discovered over 100 years earlier in Arabia.
I started roasting coffee on a Probat L12 for over 4 years ago. I would take one-step forward, and about 14 steps back, sometimes if I were lucky, only a few steps back. But every time I learned something new, there was more to the science that needed to be discovered. Today I am roasting on a 1965 Probat G45 with a few updated controls, and even though I have learned a lot during my time in the coffee industry, everyday there is something new. The funny thing about being a roaster, is that you’re never really finished learning, which can also leave you in a frustrated chase for answers.
What many people don’t understand about coffee, are the variables involved that can greatly affect a coffees flavor profile. First and foremost we need to take a look at the source of the coffee seeds, the origin.
If you don’t already know, coffee beans are really roasted seeds from a fruit known as the coffee cherry. These cherries grow on trees or “shrubs” all over the world, and are usually able to be grown between 25 degrees north and 25 degrees south of the equator.
Varietal – There are many varietals in coffee. Some of the most common are Typica, Bourbon, Caturra and Catuai, though there are roughly 60 different types of varietals. A variety in coffee can be closely related to the varieties of apples. Many are familiar with the differences between a Red Delicious apple and a Granny Smith apple; one is much sweeter while the other has a tart bite to it. The same goes for varietals in coffee, except much more subtle to notice.
Terrain/Climate – The coffee cherry thrives under sub-tropical climates with an abundance of rainfall. Can be grown between altitudes of 1800-6300 feet, depending on the latitude of the growing location. The cherry trees require moist rich soils, volcanic soils or sandy loam.
Altitude - A higher grown coffee will be a denser bean then a lower grown coffee. SHB (strictly hard bean) or SHG (strictly high grown) will be noted during the green coffee purchase so as to signify that the coffee has been grown between 4000-6000 FASL. Coffee that has been grown in a lower elevation will result in a softer and less dense bean.
This list of variables is based around coffees growing environment. There are many more variables that we will touch base on, but for now we will let this sink in with you. What I purposely failed to mention is the country it is grown in, and that’s because coffee doesn’t know governing boundaries. The major reasons why a Colombian coffee and a Peruvian coffee have different profiles regardless of the fact that they are in close proximity to each other, does not relate to their governing boarders. There are many reasons why they will taste different, but from the source alone they will be all affected by the variables that were listed above; species, varietal, terrain/climate and altitude. There are many other variables that will attribute to a coffees profile. More to come in part 2.