Coffee Production and Trade

Coffee botany and ecology

Botany

Coffee flowering

Coffee is a woody, perennial evergreen dicotyledon belonging to the botanical family Rubiaceae, which contains some 500 genera and over 6000 species. Most of these are trees and shrubs which grow in the lower storey of tropical forests. Coffea is by far the most important member of the family economically, of which two species are traded widely:

• Coffee arabica, referred to as 'arabica', which accounts for between 60% and 70% of world production.
• Coffea canephora, referred to as 'robusta', which comprises 30% to 40% of world production.

Two other species which are grown on a much smaller scale are Coffea liberica ('liberica' coffee) and Coffea dewevrei or Coffea excelsa ('excelsa' coffee), both of which are traded, but to a very limited extent.

Arabica: Original arabica strains generally produce good liquors with acidity, and have the greatest flavour and aroma characteristics, but are susceptible to pests and diseases. Resistance is thus a major goal of plant breeding programmes¹. A number of more tolerant varieties have been developed over the years, including the well known varieties 'Typica' and 'Bourbon', which are considered to be the first cultivars of arabica.

Robusta coffee cherries

Many different strains and cultivars have been developed from these, such as 'Caturra', 'Mundo Novo', 'Catuai' and 'Blue Mountain'. Generally speaking, arabica coffee is grown throughout Latin America, in Central and East Africa, in India and, to some extent, in Indonesia.

Robusta: The term 'robusta' is actually the name of a widely grown variety of Coffea canephora. It is a small tree (up to 10 metres in height) that can grow at lower altitudes than arabica, with higher yields and with better resistance to disease.

The beans, however, are of inferior taste than arabica, and have twice the caffeine content. Robusta coffee commands a lower price on the market, and is often used for soluble coffee or to give a caffeine 'boost' in espresso². Robusta coffee is grown in West and Central Africa, throughout South-East Asia and to some extent in Brazil, where it is known as 'Conillon'.

¹ Including arabica / robusta crosses which aim to improve arabica by conferring disease resistance and vigour, or to improve on the cup quality of robusta. The 'Catimor' variety is a cross between Caturra and Hibrido de Timor (a natural arabica / robusta hybrid), and is resistant to coffee leaf rust (Hemileia vastatrix).

² The distinction between arabica and robusta coffee has become more blurred in recent years. Steam cleaning technologies can improve the quality of robusta coffee, allowing it to be substituted for arabica in some markets, notably Germany.