Organic Robusta Coffee

Coffee beans are the seeds of the coffee “cherry”; two seeds normally grow within each cherry. On the tree, the beans are covered by the silverskin (a vestigial remainder of the fruit’s development, also called the spermoderm). The silverskin is covered by a parchment skin (the endocarp), which is covered by a slimy layer (the parenchyma), surrounded by a thin layer of pulp (the mesocarp), all covered by an outer skin (the exocarp). These layers must be removed prior to roasting, though some silverskin often remains attached.

The coffee’s country of origin is largely a matter of subjective taste, and you will benefit by sampling a wide variety of origins and roasting styles. Origin is important in that the comparative bean flavor between growing regions, even within the same country, can be quite different. As a result, it is difficult to make sweeping generalizations about the coffees in any particular region.

All coffee beans come from plants in the genus Coffea. Although there are thousands of species of plants within this genus, with tremendous variance in size and shape, only two are of commercial importance: Coffea arabica, and Coffea canephora, the latter more commonly called robusta, after a prime variety. A third species, Coffea liberica has found some localized production in Liberia, but it is of minor significance in the global market.

Dry processing is the oldest method of processing coffee. The cherries are washed and then spread out on drying racks to dry in the sun for several weeks, or alternatively, are dried by machine. During this drying process, the pulp ferments, lending a particular taste to the bean. How the coffee is handled during drying—whether sun-dried coffee is protected against adverse weather or temperature, the machine driers’ temperature, etc.—effects the eventual quality and flavor of the bean. After the beans are dried, they are machine processed to remove the dried outer layers.

Wet processed beans have their outer skins removed by machine processing, then the fruit with the exposed pulp is allowed to ferment in tanks where bacteria and naturally occurring enzymes consume the pulp. The beans are then washed and dried, also either by sun or machine, and the dried beans are then milled to remove the remaining layers.