Unbelievable as it may seem, more than 75% of the coffee consumed worldwide is actually derived from Coffea Arabica beans while a major portion of the remaining amount is obtained from Coffea Robusta beans (also called Coffea Canephora). These two types of coffee beans make up most of the commercially produced coffee consumed around the world (1).
Coffea Arabica is accredited with being the original coffee species to be cultivated and is indigenous to Ethiopia, a country accredited for discovering the drink. It is also referred to as ‘mountain coffee’ and ‘coffee shrub of Arabia’ and is deemed to be the best commercially grown coffee.
The Coffea Arabica plant can grow from seven to twelve meters tall, with oblong, glossy dark green leaves that are 6 to 12 centimetres long (2).
The white flowers are produced in axillary clusters and transform into the fully developed fruit (the cherry) ranging in size between ten to fifteen millimetres. Initially the cherries are green, but they turn from a deep red to purple shade upon maturity. Each sweet edible fruit houses two seeds (the coffee beans) inside, which are bitter tasting.
Growing Coffea Arabica is difficult as it is sensitive to the environment and more susceptible to disease than Coffea Robusta. This is explained by the fact that Coffea Robusta houses approximately twice the caffeine found in Coffea Arabica and it acts like a natural insecticide.
When insects try to eat the Robusta plant, they are paralyzed or killed. The ease of growing and its ability to withstand harsh conditions have resulted in robusta becoming the cheaper and somewhat inferior quality substitute for Arabica in a large number of the blends and almost all instant coffees.
The various varieties of Arabica coffees range in taste from mildly sweet to sharp and tangy. Their unroasted beans smell like blueberries and once roasted the smell turns sugary and fruitier.
Robusta however produces coffee that has a more bitter taste with a smell that resembles ‘burnt rubber’. Good quality robusta’s are uncommon but available in Italy where dark roasted robusta’s are appreciated for the crema they produce on espressos.
There are a large number of Coffea Arabica varieties grown around the world and most of them are named after the region in which they are cultivated. Ethiopia is known for growing several highly valued varieties which are referred to according to the specific region in the country where they are cultivated.
South and Central America are major coffee producers with Colombian coffee from the region being rather famous.
The well-liked varieties include bourbon, Maragogype, Caturra and Typica. From Guatemala comes Huehuetenango, named after the city in the vicinity of where it is grown in the Cuchumatan mountains. Brazil offers the Santos variety, Uganda provides Bugishu and Indonesia offers Java.
A third type of commercially grown coffee bean is Liberica. It accounts for less than two per cent of the total coffee production in the world. Grown primarily in Malaysia, it is comparable in quality to Coffee Robusta. Coffee beans from Liberica plants are more boat shaped and larger as opposed to the smaller and oval shaped beans of Arabica and round beans of Robusta.