HomeThe Coffee Plant
Coffee grows exclusively in tropical and sub-tropical regions. The present coffee-producing belt around the globe comprises about 70 countries involved in cultivation, and lies between the latitudes of 23 degrees north and 25 degrees south. The ideal growing conditions for coffee trees are an average of 17 degrees Celsius to 23 degrees Celsius as well as abundant precipitation and fertile soil.
The coffee plant is a tree that belongs to the gender Coffea. There are more than 60 different varieties of coffee, but for trade purposes the Coffea Arabica (Arabica) and Coffea Canephora (Robusta) are the most important.
In some parts of Africa, the coffee tree still grows in the wilderness, mainly at the Ivory Coast, Uganda and Zaire. Depending on the type, the coffee tree can reach a height of 10 to 15 metres. On the plantations, however, continual pruning prevents the trees from growing taller than 1.5 to 3 metres. This ensures a high yield and makes harvesting easier.
The tree's leaves are broad, dark green and shiny, similar to those of a camellia bush. The blossoms are white, star-shaped flowers and resemble the flowers of the Jasmine tree in fragrance, colour and appearance.
The coffee bean is the seed of the berry. It resembles a cranberry and has a sweet pulp, protected by a membrane called parchment and a silky thin membrane called silverskin. Coffee beans are actually the two flat-sided seeds inside the cherry. Unprocessed coffee is called green coffee.
Coffee Varieties
The various types of coffee are distinguished by the variety and origin (highland or lowland), the flavour and the aroma. Arabica is a well-flavoured, aromatic coffee with less caffeine than Robusta, which has a somewhat unrefined, earthier taste.
Highland coffees have a particularly fine aroma and are cultivated on plantations at an altitude of 600 to 1,800 metres above sea level. Lowland coffees have a different flavour and originate from plantations at lower altitude. In general the higher the altitude, the more superior the quality of coffee produced. However, this is not always the case, since plantations at lower altitude can also produce very good quality coffee.
While both widely cultivated, Coffea Arabica (Arabica) and Coffea Canephora (Robusta) display marked differences. The beans are different. The plants are different. And consequently, the use varies as well.
Arabica is the oldest species of bean and is the most widely cultivated, accounting for 74 percent of the beans grown in the world. Arabica beans grow at altitudes between 600 and 1,800 metres above sea level and take six to nine months to mature. The Arabica beans command a higher price on the coffee market because growing coffees at higher altitudes is more expensive and labour-intensive. Arabica beans fall to the ground soon after they ripen, so they must be harvested as soon as they are ripe to prevent them from spoiling or absorbing flavour taints from the ground. High-grown coffees are also at risk of frost damage, so farmers tend to build plant replacement costs into their prices. Production costs are higher since most Arabicas, especially those grown at the highest altitudes, are hand-picked and processed in the more expensive wet method.
The Robusta plant was discovered in the 1870s, growing wild in the Congo. About 26 percent of the world coffee trade consists of Robusta beans. Robusta today is mainly cultivated in West Africa and Southeast Asia. Robusta trees are very hearty plants that grow at lower altitudes (sea level to 600 metres) and are more cold- and moisture-tolerant and disease-resistant than the delicate Arabicas. Robustas mature in about half the time of Arabicas and yield almost twice as many berries. Unlike Arabica beans, Robusta beans do not fall off the tree when they become ripe, so they don't need immediate harvesting. Robustas are also used for commercial, canned and instant coffees. Because they are cheaper to produce, Robustas are sometimes combined with Arabicas to make a low-cost blend with some of the flavour characteristics of the more expensive Arabica beans.
Perhaps the most significant difference rests in the cup.
Arabica is distinctly milder and more aromatic. It possesses fewer sharp and bitter tastes than Robusta, and it is therefore considered the superior species by those who cultivate specialty coffees, single estates and varietals.
Robusta is renowned for its higher caffeine content, which is why Italians began using it for espresso.
The coffees are also botanically different. Arabica’s greater complexity derives from its 44 chromosomes – twice the number of Robusta. An Arabica bean is flatter and more elongated; in addition, and the furrow on its flat surface is elongated. It is relatively deep green in color before roasting, sometimes with a bluish tinge.
The Robusta bean is more convex and roundish. The bean’s furrow is straight, and it is pale green with grey or brownish tinges.
Arabica is the more expensive of the two, another factor in why Robusta is sometimes used in blends.
| 