The Science of Coffee
Coffee is a caffeinated beverage brewed from the roasted seeds of an evergreen shrub of the genus Coffea. While the beverage is speculated to have its origins in Ethiopia, the first evidence of coffee in its current form appears in the middle of 15th century Arabian Peninsula in the Sufi shrines of Yennen. Slightly acidic, this beverage is prized for its distinct flavor and its ability to fuel productivity and spark creativity.
The primary active ingredient in coffee is caffeine. When caffeine enters the bloodstream and reaches the brain, it blocks a sleep related brain chemical called adenosine, tricking the brain into thinking it is in a state of emergency. This activates the pituitary gland which begins to release adrenaline causing the heart to quicken, the eyes to dilate, and the liver to release extra sugar into the bloodstream. The rush of adrenaline gives the drinker a feeling of renewed vigor, increasing alertness, and boosting productivity.
Quality and Planting Elevation
The coffee beans are actually seeds found within the pits of cherries of the coffee plant. These seeds may be planted to grow a coffee shrub. Elevation has a profound impact on the flavor of coffee. In general, higher elevations provide the ideal conditions necessary to prolong the maturation process of the bean. This ensures that the bean has time to develop more complex sugars and interesting flavors, creating a more distinct and intricate flavor profile. The best coffees are grown close to the equator between 4,000 and 6,000 feet, where the climate is still frost free, rainfall is moderate, and the sunshine is abundant.
There are two major methods in processing coffee cherries, the dry method and the wet method. In the dry method, coffee cherries are laid out in the sun to dry, raked and turned throughout the day to prevent spoiling, then covered at night or during rain. This ancient method may take weeks depending on the climate.
In the wet method, fresh coffee cherries are fed through a pulping machine which isolates the beans. The pulp is washed away and used as mulch, while the beans are further processed through water channels allowing the heavier ripe beans to sink. The beans are separated further by size, transported to large fermentation tanks, where they are soaked to allow the enzymes to remove the outer layer of parenchyma from the surface of the bean.
After 1-2 days, fermentation leaves the beans rough to the touch and ready for drying. They will either be dried in tumblers or on drying tables and floors until 11% moisture content. Once dry the beans are referred to as parchment coffee, as there is still an external layer called the endocarp covering the bean. To remove this, the beans are passed through a hulling machine and may be subjected to polishing depending on the process. Once clean the beans are exported and packaged into coffee bags, fresh and ready for brewing.