as told by lattelandkc.com
Me, being a coffee consumer, am interested in this. You may be too.
The coffee tree & its remarkable berries were first discovered growing wild in the region now known as Ethiopia. Coffee was first prepared not as a beverage but as a food. African tribes would use stone mortars to crush the ripe cherries from wild coffee trees, mix them with animal fat & then fashion this exotic blend into round balls, which they consumed on their war parties.
Around 1000 A.D. the neighboring Arabs began to boil the dried, crushed seeds to make a hot drink. Due to religious, medical, & commercial considerations, the spread of the bean through Arabia & subsequently Europe/the Americas was impeded by prohibitions & powerful restrictions on the export of trees & Cultivatable seeds. The result - intrigue.
In the early 1700's, a coffee tree reached Paris, France & was kept in the Jar din des Plantes, bringing great celebrity to the royal botanist, Antoine de Jussieu. A young naval officer serving in the New World, in Martinique, thought that by taking seedlings back to the Indies he might introduce a profitable new crop to the French colony. His name was De Clieu.
De Clieu approached de Jussieu with his plan, but seeing his fame at stake, he refused. De Clieu then sought out Monsieur de Chirac, the royal physician. Finally persuaded by the intervention of a beautiful lady of high rank, Chirac enabled De Clieu & his companions to steal over the walls of the Jar din des Plantes & make off with cuttings from the coffee tree. A single plant survived in De Clieu's garden, producing a great many viable seeds. It's said that the huge coffee industries of the New World- from Mexico to Brazil- grew from this one tree.
Coffee beans are the seeds of the ripe fruit from the coffee plant which is a member of the family Rubiaceae, genus Coffea. It is classified as a perennial evergreen dicotyledon, which means that it is always green and has two seeds per cherry. The coffee plant is a large bush or shrub with oval, waxy leaves. The plant is commonly referred to as a tree and can grow up to a height of forty feet.(Most trees are kept shorter for easier harvest.) At three to four years the plant produces its first flowers, which give way to clusters of oval berries, which are green and gradually ripen to a bright red over a period of about six months. At this point the cherries are ready for harvesting and processing.
There are two primary species of coffee: Arabica and Robusta. Arabica grows best between altitudes of 4000 and 6000 feet, in areas where the temperature stays between 60 and 75 degrees Fahrenheit. High grown coffees produce a much more dense and flavorful bean. Arabica accounts for 70% of the world's coffee production. Most specialty coffee and all of Intelligentsia's coffee is Arabica.
Typica and Bourbon are the oldest and best-known varieties of Arabica Coffee, but many strains have been developed, including Caturra, Mundo Novo, Tico, San Ramon and Jamaica Blue Mountain.
Robusta grows at lower elevations, can tolerate greater swings in temperature, is more resistant to disease, and yields a higher amount of fruit. We feel that Robusta produces a harsher flavor in the cup. Most canned, instant, or cheap supermarket coffees use Robusta.
After the coffee beans are harvested. There are two ways in which they are prepared for roasting:
The traditional and oldest method of processing coffee. The ripe cherries are spread over a flat surface and left in the sun to dry. The beans are raked at regular intervals to prevent fermentation and rotting. If it rains, the cherries must be protected from moisture to prevent mold, fungus, or uneven drying. After the cherries are dried, they are hulled and further prepared for export.
The wet method is employed immediately after harvesting. If a coffee is referred to as "washed", it is wet-processed. The wet method utilizes fresh water throughout the processing. This method requires a constant supply of fresh, clean water and more resources than dry processing.
After the beans are harvested,they are loaded into trucks and transported to a mill. (Small farm owners often pool resources to utilize the expensive machinery of the mills.) The cherries are unloaded into large tanks of water. Sticks, leaves, and lightweight cherries float to the top, while ripe cherries sink to the bottom. The floaters are pulled and spread to dry sun dry on the patios. (Very little coffee is wasted; lesser quality beans are sold for lower prices, and used in cheaper blends or domestic coffees.) The ripe cherries are sent through a de-pulping machine, which strips away the fleshy outer layer. Mechanical graders, which separate beans by weight and size, sort the beans again. Generally, the consistently larger and denser beans are considered to be a higher grade of coffee. (The more consistent the size and density of the bean, the more consistent the roast and flavor will be.) Exporters and Importers refer to these as "A's" and "B's".
The various sorts, or grades, of beans are then fermented in large tanks of water for 12 to 48 hours, during which time natural enzymes break down the outer layer (parenchyma) from the parchment-like covering (endocarp) Fermentation time depends on the altitude where it is performed, some farmers simply grab a handful of beans and determine the time by feel.
The beans are then dried to retain 11% moisture content. Most farms will use concrete patios and the sun to do this, a process which can take anywhere from 7-15 days. The beans are raked to ensure even drying and have to be protected from moisture. Some modern mills use mechanical driers which expedite the drying process and allow greater control.
The beans are then rested in silos. This step allows them to stabilize chemically, and moisture content is evenly distributed. Another step to ensure the consistency of the final product.
In wet processed coffee, hulling refers to the removal the dried parchment layer immediately surrounding the bean. Hulling dry processed coffee refers to removing the husks or whole dried outer covering of the original cherry.
Polishing in not always done, but refers to the removal of any remaining silver skin on the bean. Some claim that polishing gives the end product a cleaner, more refined flavor in the cup.
Grading & Sorting
The beans are then further subjected to a variety of sorting which focuses primarily on size, density and color. Mechanical shakers are used to sort by density, and an electric eye searches for defects: scanning for pits, discolorations, broken edges, and other malformations. There are always defects in every lot, but one single bad bean can ruin a cup of coffee. Finally, high quality coffees are sorted by hand; machines can never compete with a well-trained, discerning human eye.
It is impossible to understate the importance of processing coffee. At any one step, if things are mishandled, even slightly, entire harvests can be ruined. If beans are left too long unraked on a patio, they will begin to mold, producing a grassy, fermented taste in the cup. If dried too quickly, the acidity of the bean will fade greatly and it will taste dull and lifeless. The amount of work that goes into a single cup of coffee is staggering. When you witness the entire process from beginning to end, it is a wonder that a cup of coffee sells for as little as it does.