There are two basic categories into which all species of coffee trees can be sorted. Although there are several varieties of each—each variety having its own character—this division into two large categories is useful for understanding the difference between a gourmet cup of coffee and an ordinary cup. High quality blends consist of 100% Arabica beans. Lower quality, cheaper blends may have some proportion of Robusta beans, or they may consist entirely of Robusta. Arabica beans produce a superior taste in the cup, being more flavorful and complex than their Robusta counterparts. Robusta beans tend to produce a more bitter brew, with a musty flavor and less body.

There are two distinct processing methods, dry and wet.

Dry Method:

Fresh cherries, which are dried whole without pulping are milled when thoroughly dried to remove the dehydrated pulp, parchment skin, and silver skin in one operation. The product is green coffee, ready for grading and bagging, and is often called "natural coffee."

Wet Method:

It involves the removal of the pulp, fermentation of the mucilaginous material covering the parchment skin, rinsing, and then drying. Most countries producing mild coffee use the wet method. A variation of the wet method is mechanical demucilization. The Fukunaga (CTAHR) hydro-pulper is an example of a machine for this purpose.

Steps:

1)     Remove the outer skin of the cherry and the pulpy flesh beneath it. This flesh and the fruit skin are collectively called the "pulp" after their removal in a process called "pulping."

2)   Beneath the fruit flesh is a layer of slimy, mucilaginous matter, and beneath it is the    parchment skin, a very tough, almost shell-like coating that is difficult to remove. The mucilaginous layer is removed after the harvested cherries are pulped, either by natural fermentation during soaking or by mechanical means.

3)      Coffee beans when dried and ready for milling are covered by their parchment skin and are referred to as "parchment coffee."