Coffee beans come in two commercially significant varieties: Arabica and Robusta. The finer Arabica makes up 70% of the world's production. Robusta is widely used for coffee blends and instant coffee. Countries such as Colombia, Ethiopia, Costa Rica, Nicaragua and Kenya grow little but Arabica beans whereas newcomer Vietnam almost exclusively produces Robusta.
The world's most exotic and expensive coffee comes from Indonesia. Kopi Luwak is made from coffee cherries that have been eaten, digested and excreted by a small marsupial. The coffee has a rich, heavy and exotically earthy flavour with a hint of caramel or chocolate. No more than 200 kg are produced a year – at prices of up to 1,000 euros a kg. Coffee merchants assure us the beans are washed before roasting.
Origin coffees contain beans from a single country while blended coffees are made from beans of various origins to make a cup of varying acidity and taste. Since different batches of coffee from the same source are likely to taste different, blending is one way of achieving constant quality.