Coffee bean types
There are two main species of the coffee plant; Arabica is the traditional coffee, and considered superior in flavor. Robusta, which is higher in caffeine, can be cultivated in environments where Arabica will not thrive, leading to its use as an inexpensive substitute for Arabica in many commercial coffee products. Robusta is not usually consumed by itself, due to its bitter and acidic flavour. Higher quality Robustas are used as ingredients in some espresso blends.
Arabica coffees were traditionally named by the port they were exported from, the two oldest being Mocha and Java. The modern coffee trade is much more specific about origin, labeling coffees by country, region, and sometimes even the producing estate. Coffee aficionados may even distinguish auctioned coffees by lot number.
One unusual and very expensive variety of robusta is the Indonesian Kopi Luwak. The beans are collected from the droppings of the Common Palm Civet, whose digestive processes give it a distinctive flavour.