Landscape of Sumatran coffee growing region
Climate and growth
Ernesto Illy wrote in the June 2002 issue of Scientific American, Arabica is “a medium to low wielding, rather delicate tree from five to six meters tall that requires a temperate climate and considerable growing care. Commercially grown coffee bushes are pruned to a height of 1.5 to 2 meters. Coffee made from arabica beans has an intense, intricate aroma that can be reminiscent of flowers, fruit, honey, chocolate, caramel or toasted bread. Its caffeine content never exceeds 1.5 percent by weight. Because of its superior quality and taste, arabica sells for a higher price than its hardy, rougher cousin.”
Wild plants grow to between 9 and 12 m tall, and have an open branching system; the leaves are opposite, simple elliptic-ovate to oblong, 6–12 cm long and 4–8 cm broad, glossy dark green. The flowers are white, 10–15 mm in diameter and grow in axillary clusters. The fruit is a drupe (though commonly called a “berry”) 10–15 mm in diameter, maturing bright red to purple and typically contains two seeds (the coffee ‘bean’).
C. arabica takes about seven years to mature fully, and 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 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 when the temperature hovers around 20 °C (68 °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.
Arabica coffee flowers
Flowers and berries
Two to four years after planting, C. arabica produces small, white and highly fragrant flowers. The sweet fragrance resembles the sweet smell of jasmine flowers. When flowers open on sunny days, this results in the greatest numbers of berries. This can be a curse, 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 favour the ripening of berries to the detriment of its own health. On well kept plantations, this is prevented by pruning the tree. The flowers themselves 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’ 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, the ripe and unripe berries being collected together.
Australian Arabica Coffee
The trees are difficult to cultivate and each tree can produce anywhere from 0.5–5.0 kg of dried beans, depending on the tree’s individual character and the climate that season. The real prize 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, there is sometimes a third seed or one seed, a peaberry in the fruits 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.” See Informed Farmers coffee cultivar & nursery articles for additonal information.
Source
Kauai Coffee Company, About.com
