Coffee Processing and Coffee Quality
Coffee beans are not beans at all in a botanical
sense. They are the twin seeds of a red (sometimes yellow) fruit
that grows to about the size of the tip of your little finger.
Growers call these coffee fruit coffee cherries. Before the coffee
can be shipped and roasted, the bean or seed must be separated
from the fruit. Nature has been lavish in its packaging of the
coffee seed, and removing the three sets of skin and one layer
of pulp from around the seed is a complex process. If done properly,
the coffee looks better, tastes better, and demands a higher price.
The worst preparation or processing would be as
follows: The coffee berries are stripped -- leaves, unripe berries,
and all -- onto the ground. This mixture is then scooped up, sifted,
and dried in the sun (and sometimes in the rain, which is one
of the problems with such coffees). Later the dried, shriveled
fruit is stripped off the bean. Some beans may be small and deformed,
shriveled, or discolored. In very poorly prepared coffee all the
beans, good and bad, plus a few twigs, a little dirt, and some
stones, are shipped together. The various flavor taints associated
with cheap coffee -- sourness, mustiness, harshness, composty
taste -- all derive from careless picking, fruit removal and drying.
The best preparation would run like this: The
coffee cherries are selectively picked as they ripen. The same
day they are picked, the outer skin is removed, exposing the pulp.
The pulp-covered beans are then subject to controlled fermentation
in tanks. The ferment-loosened, flabby pulp is then gently washed
off the beans and they are dried, after which the last layers
of skin, now dry and crumbly, are stripped from the bean by machine.
Between these two extremes -- carelessly picked
coffees simply put out into the sun to dry and selectively picked,
wet-processed coffees -- are coffees that have been dried in the
old-fashioned way, with the fruit still clinging to the bean,
but have been picked selectively and dried with care. These high-quality
dry-processed or "natural" coffees can be superb, alive
with fruity nuance.