Botanical drawing of Coffea arabica, around 1860
Botanical drawing of C. arabica, dating from around 1880.
Arabica coffee’s first domestication in Ethiopia is obscure, but cultivation in Yemen is well documented by the 12th century.
Coffea arabica accounts for 60% of the world’s coffee production.
C. arabica takes approximately seven years to mature fully, and it does best with 1.0–1.5 meters (about 40–59 inches) of rain, evenly distributed throughout the year. It is usually cultivated between 1,300 and 1,500 m altitude, but there are plantations that grow it as low as sea level and as high as 2,800 m.
The plant can tolerate low temperatures, but not frost, and it does best with an average temperature between 15 and 24 °C (59 and 75 °F). Commercial cultivars mostly only grow to about 5 m, and are frequently trimmed as low as 2 m to facilitate harvesting. Unlike Coffea canephora, C. arabica prefers to be grown in light shade.
Two to four years after planting, C. arabica produces small, white, highly fragrant flowers. The sweet fragrance resembles the sweet smell of jasmine flowers. Flowers opening on sunny days result in the greatest numbers of berries. This can be problematic and deleterious, however, as coffee plants tend to produce too many berries; this can lead to an inferior harvest and even damage yield in the following years, as the plant will favor the ripening of berries to the detriment of its own health.
On well-kept plantations, overflowering is prevented by pruning the tree. The flowers only last a few days, leaving behind only the thick, dark-green leaves. The berries then begin to appear. These are as dark green as the foliage, until they begin to ripen, at first to yellow and then light red and finally darkening to a glossy, deep red. At this point, they are called “cherries,” which fruit they then resemble, and are ready for picking.
The berries are oblong and about 1 cm long. Inferior coffee results from picking them too early or too late, so many are picked by hand to be able to better select them, as they do not all ripen at the same time. They are sometimes shaken off the tree onto mats, which means ripe and unripe berries are collected together.
The trees are difficult to cultivate and each tree can produce from 0.5 to 5.0 kg of dried beans, depending on the tree’s individual character and the climate that season. The most valuable part of this cash crop are the beans inside. Each berry holds two locules containing the beans. The coffee beans are actually two seeds within the fruit; sometimes, a third seed or one seed, a peaberry, grows in the fruit at tips of the branches. These seeds are covered in two membranes; the outer one is called the “parchment coat” and the inner one is called the “silver skin.”