Coffea arabica

Coffea arabica (pronounced /əˈræbɪkə/) is a species of coffee indigenous to Ethiopia and Yemen. It is also known as the "coffee shrub of Arabia", "mountain coffee" or "arabica coffee". Coffea arabica is believed to be the first species of coffee to be cultivated, being grown in southwest Arabia for well over 1,000 years. It is considered to produce better coffee than the other major commercially grown coffee species, Coffea canephora (robusta). Arabica contains less caffeine than any other commercially cultivated species of coffee. 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 contain two seeds (the coffee 'bean').

Cultivation
Coffea arabica takes about seven years to mature fully and does best with 1-1.5 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, Coffea arabica prefers to be grown in light shade.
Two to four years after planting Coffea 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 favor 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 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' and the inner one is called the 'silver skin'.

Drawing of Coffea arabica
In perfect conditions, like those of Java, trees are planted at all times of the year and are harvested year round. In less ideal conditions, like those in parts of Brazil, the trees have a season and are harvested only in winter. The plants are vulnerable to damage in poor growing conditions and are also more vulnerable to pests than the Robusta plant. Gourmet coffees are almost exclusively high-quality mild varieties of coffea arabica, like Colombian coffee.
Arabica coffee production in Indonesia began in 1699. Indonesian coffees, such as Sumatran and Java, are known for heavy body and low acidity. This makes them ideal for blending with the higher acidity coffees from Central America and East Africa.

Coffea arabica plantation, São João do Manhuaçu, Minas Gerais, Brazil

Unroasted coffee(Coffea arabica) beans - Brazil

History and legend
Main article: Coffee
According to legend, human cultivation of coffee began after goats in Ethiopia were seen mounting each other after eating the leaves and fruits of the coffee tree. In reality, human consumption of coffee fruits probably began long before humans took up pastoralism. In Ethiopia there are still some locales where people drink a tisane made from the leaves of the coffee tree.
The first written record of coffee made from roasted coffee beans comes from Arabian scholars who wrote that it was useful in prolonging their working hours. The Arab innovation of making a brew from roasted beans, spread first among the Egyptians and Turks and later on found its way around the world.

Research
Brazilian biologists have found 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 Coffea arabica plants. While beans of normal Coffea arabica plants contains 12 milligrams of caffeine per gram of dry mass, these newly found mutants contain only 0.76 milligrams of caffeine per gram with all the taste of normal coffee. ln addition, coffee beans have been discovered in the North-eastern part of Nigeria, a region called Sardauna.

Structure of coffee berry and beans:

1: center cut

2:bean (endosperm)

3: silver skin (testa, epidermis),

4: parchment (hull, endocarp)

5: pectin layer

6: pulp (mesocarp)

7: outer skin (pericarp, exocarp)