Coffee: The Bean and More

Coffee is the most consumed beverage and widely cultivated around the world. Having seen the coffee plant as short and pruned shrub, it is surprising to know that the coffee plant can grow as high as 30 feets! The leaves are dark-green in color, are waxy in texture and grow in pairs opposite each other. The coffee cherries develop from white blossoms and grow alongside the branches of the tree. It takes about one year for the cherries to get matured. These cherries can be seen in different cycles of growth like flowers, green fruit and ripe cherries, in the same tree. The coffee tree has a life span of about 20-30 years. The climatic conditions optimal for growth of coffee tree include rich soil and mild temperature. These trees cannot withstand extreme fluctuations in temperature and prefer frequent rains and shaded sun.

The coffee plant

The coffee plant belongs to the genus Coffea, which includes about 500 genera and 6,000 species of tropical trees and shrubs. Since its description in 18th century by the Swedish botanist, Carolus Linneaus, the exact classification of coffee is still debatable. The reasons include:

• The coffee plant has about 25-100 species
• The plant can range from small shrubs to tall trees
• The size of the leaves vary from 1 to 40 centimeters
• The color of the leaves may range purple, yellow to dark green

The coffee fruit/cherry

Fruit has an outer skin called exocarp, and a middle mesocarp consisting of a thin pulp layer and a slimy layer called parenchyma. The endocarp that covers the beans is a parchment like envelope, inside which lie two beans side by side. Each bean is covered by their individual layer of thin membrane called spermoderm. This spermoderm is alos referred to as silver skin in the coffee trade.

Important coffees

There are two important varieties of coffees- arabica and canephora, more commonly called robusta.

Coffea arabica

Coffea arabica claims about 70% of the total in the world. The coffee is fine, mild and aromatic. Coffee arabica descended from the original coffee trees discovered in Ethiopia, and is grown between 2,000 to 6,000 feet above sea level. The species need mild temperature and between 59 - 75 degrees, with about 60 inches of rainfall a year. Presence of heavy frost can be detrimental to their growth. These plants grow on terrains that are steep and difficult to access, therefore, cultivation becomes costly. The trees require extra care as they are prone to infestations. As compared to the robusta variety, the beans of Coffee arabica tend to be flatter, and more elongated, and have less caffeine content.

Coffea canephora/robusta

Robusta coffee accounts for about 30% of the coffee production of the world, and is grown in Central and Western Africa, parts of Southeast Asia, including Indonesia and Vietnam, and in Brazil. The robusta tree is easier and cheaper to cultivate as they are resistant to infestations, and can grow in warmer climates. As compared to arabica, It can grow at lower altitudes between temperatures of 75 and 85 degrees, with a rainfall of about 60 inches a year. However, like arabica, it cannot withstand frost. Robusta beans are round and small, and have a distinctive taste. It has 50-60% more caffeine, and is used in blends and instant coffees.