Botanic Name: coffea arabica
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 Arabica 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. One information source cites Arabicas as growing best in altitudes of 5,000 to 6,000 ft. 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.
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, which means that ripe and unripe berries are collected together.
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.”
There is an Ethiopian Coffea arabica that naturally contains very little caffeine. Maria Bernadete Silvarolla, a researcher of Instituto Agronomico de Campinas (IAC), published findings in the journal Nature about these strains of C. arabica plants. While beans of normal C. arabica plants contain 12 milligrams of caffeine per gram of dry mass, these newly found mutants contain only 0.76 milligrams of caffeine per gram, but with all the taste of normal coffee. During an evaluation of Australian coffee at the International Food Institute the average caffeine content for New South Wales coffees was 1% which is significantly lower than most overseas arabicas which range from 1.16% to 1.20% caffeine.
In Thailand during 1989 the late Princess Mother called for the introduction of coffee as an alternate crop for hilltribe farmers in northern Thailand as part of a development project to help restore the ecological balance of the region. The Nestlé Experimental Coffee Development Farm was established in Doi Tung, Chiang Rai province, with partner organisations the Doi Tung Development Project and Mae Fah Luang Foundation.Under this project, 22,000 seedlings of 57 Arabica coffee varieties were planted to determine those most suitable for cultivation in northern Thailand. Two of these varieties were identified as suitable for cultivation in the hillsides. Since the project began, more than 1.5 million improved Arabica seedlings have been provided to hilltribe farmers. In 2009, the capital income of farmers in this area had improved tenfold since the beginning of the previous decade. Mrs. Yue-Yee Abegu – aged 57, an Arkhar worker at Nestlé’s Arabica Experimental & Demonstration Farm at Doi Tung, Chiang Rai Province spoke about her experience working at Doi Tung, “Before the Doi Tung Development project has been established, I planted rice and opium poppy. They were difficult to handle. The plantation needs lots of fertilizer. Despite that production was low and income was not good. Then after Nestlé has joined the Doi Tung Development Project, I started working with the Nestlé at the very beginning. It has been 17 years by now. We have quit planting opium poppy for a very long time and turn to plant coffee instead because it yields good price. Handling is easier not complicated. It needs only 3 times a year to fertilize. At present our family makes a much better living than before. And we are happy.”
The Australian Queensland Department of Primary Industries in conjunction with Rural Industries Research & Development Corporation, research program findings on the (potential for a viable mechanised) coffee industry in Australia are covered in other Informed Farmers Coffee articles.
Nestle projects website