What is Coffee?
A coffee tree is actually a shrub, and coffee beans are actually seeds. Coffee trees, which can live up to 100 years, are pruned short to conserve their energy and aid in harvesting, although wild coffee plants can grow to nearly 30′ in height. The average coffee tree produces about 10 pounds of coffee cherry per year, or 2 pounds of green beans.
A coffee bean is comprised of 5 primary components: pulp (skin), mucilage (sugars), parchment and silver skin (chaff) and seeds. After harvesting, every part but the seed and silver skin is removed via a variety processes, all of which influence the bean’s flavor characteristics in much the same way as roasting seeks to bring them out.
There are over 6000 documented species of coffee, with Arabica and Robusta being the most widely cultivated. Arabica represents approximately 70% of the world’s coffee production with Robusta at nearly 30%. Arabica is the finer of the two varietals, used in specialty coffeeshops, but for a small percentage of Robusta often added to espresso to enhance the crema. Robusta is most notable for its high caffeine content, nearly double that of Arabica. It is also used for instant coffee or farmed for its caffeine which serves as an additive in sodas, energy drinks , caffeinated marshmallows during the holiday season and medical research, among other fine examples.
[Esselon Coffee Roasting Co. expressly uses 100% Arabica coffee beans.]
Natural or Dried in the Fruit Process [Dry]: Coffee cherries are sun-dried on brick or cement patios or in raised drying beds, then raked or turned by hand to ensure uniformity. Sugars from the drying cherry imbue the coffee bean with sweetness and impart more soluble solids to the bean that amplify its body. Natural process method is often used in countries where rainfall is scarce and long periods of sunshine are available to dry the coffee properly.
Benefit: Sweet, complex and heavy in body.
Esselon Coffee: Brazil Cerrado, Ethopia Sidamo Oromia
Honey Process: Skin and pulp are removed, but some or all of the mucilage (Honey) remains. Beans are then dried one of 3 ways: on patios or beds, in partial shade, or full shade. The beans they produce are classified as yellow, red or black, displaying the degree to which sugars caramelize on the parchment. This in turn affects sweetness, acidity and body.
Benefit: Decreases acidity, increases sweetness and body depending on drying time.
Washed Process [Wet]: Skin, pulp, and mucilage are removed using water and fermentation. Coffee beans are sun-dried on a cement patio or waist-high drying tables. The Kenyan wash process, the most complex and labor-intensive of all, involves (2) fermentation cycles, a water scrub then a 24 hour soak which produces remarkably complex and clean coffee beans.
Benefit: Clean, bright, and fruity.
Esselon Coffee: Colombia Santa Barbara Estate Excelso E/P, Costa Rican SHB E/P, Guatemala Huehuetenango Adiesto SHB, Mexico H/G, Sumatra Aceh Ketiara
Drying is critical to the quality and stability of green coffee. Coffee that has been over-dried will become brittle and produce too many broken beans during hulling. On the other hand, coffee that has not been dried sufficiently will be too moist and fall victim to rapid deterioration via fungi and bacteria.
Beans are dried to approximately 11% of the original moisture though either natural means (sunlight) or mechanical dryers as needed. This moisture dissipates during the roast process, most notably at 1st Crack where the bean rapidly expands as the remaining moisture is converted into steam and released from the bean.
E/P (European Preparation)
European Preparation refers to the hand process of removing defective beans and foreign matter (pebbles) from a given amount of green beans. European Preparation allows up to 8 defects per 300g of beans.
A/P (American Preparation)
American Preparation also refers to the hand process of removing defective beans and foreign matter from a given amount of green beans. Unlike the European Preparation method, A/P allows up to 23 defects per 300g of beans, a standard not generally seen in single-origin specialty coffees.
Coffee Grading by Size
Many countries classify coffee beans by using a screen size sorting system. The idea is to identify, using size as a marker, the best beans in a lot. Generally speaking, the larger a coffee bean, the slower its development. The slower the development, the greater the complexity of the bean. Although there are a number of exceptions, size is a positive indicator of bean development, and uniformity in size helps ensure a consistent roast.
Screen sizes are measured to the 64th of an inch. Coffee that is labeled “17/18″ means the beans are either 17/64″ or 18/64”. 17/18 usually denotes the highest quality Arabica beans of a given country, though 19/20 is also a classification, but far less common.