What is 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.

Arabica and robusta?
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.

Arabica is genetically distinct as it has four sets of chromosomes, whereas robusta, has two. All but one of the coffee beans Java Momma carries is Arabica.

Sensory descriptions
The taste of arabica beans differ between varieties and growing regions–the same variety grown in different parts of the world will taste different. These taste notes can be as varied as berries (blueberry is often particularly noted in Ethiopian Harrar), earthy (a characteristic associated with Indian and Indonesian coffees,) citrus (common with Central Americans), or chocolate.

On average, a robusta will be harsher. One importer likened a particularly bad origin to dung (blechh), though very fine robustas can, potentially, compare favorably to a quality arabica. Premium robustas are essentially reserved for espresso blends, where they are primarily used to greatly improve the crema and to add a certain bite to the shot. The difficulty is in finding an exceptional robusta; growers and processors are often not willing to dedicate as much effort to robusta as they are to arabica since the only potential market is for those blends. Robustas are rarely sold straight; instead, in addition to premium robustas used in espresso blends, poor quality robustas may be added to freeze-dried coffees or to coffee-flavored frozen drinks where the sugar and cream overwhelm the off-notes. Robusta has notably more caffeine than arabica.

Over sixty-five percent of the coffee grown throughout the world is arabica, but much of it is unexceptional. On its own, the label “arabica” is no assurance of quality: you will need to know much more about it and find a reputable retailer who can provide much more information, and who has sampled (“cupped”) each lot. As noted, although Brazil grows some excellent coffee, a sizeable portion of the arabica grown there is of quite poor quality, to the point where the coffee trade uses a particular term, “Rioy” (from Rio de Janeiro), to describe certain particularly harsh, pungent coffees.

As with most foods, although there are some objective factors, taste is ultimately subjective. While very few people will find Vietnamese robusta enjoyable, not everyone will agree that Jamaican Blue Mountain is the epitome of flavor. As a broad rule, all-arabica blends will considerably taste better, but a superior robusta may fare better than a poor quality arabica.

How important is the beans’ country of origin?
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 generalizations about the coffees in any particular region.

Take the Quiz

See how well you remember the lesson!