The next step after harvesting is to remove
the beans from the surrounding fruit pulp, which is done by either the
washed (wet process), or the unwashed (dry process). The latter, dry
processing, is the separation method, used where there is a shortage of
water or equipment, or both. Because most robusta and much low-quality
arabica coffee is dry-processed, many people, experts included, wrongly
assume that any dry-processed or "natural" coffee, must be inferior. On
the contrary, most of Ethiopia's wonderful varied arabicas are
dry-processed, and some of these are world class coffees; almost all
Brazilian arabicas are naturals, or unwashed, and there are some
superbly smooth, sweet and full-bodied Santos beans.
In spite of its description, dry
processing begins with the washing of the newly harvested cherries, not
only to clean the cherries but to implement another sorting procedure,
as the floaters - defective beans due primarily to insect infestation or
over-ripeness - are easily picked out at this stage. The cherries are
then spread out to sun-dry; if on patios they are raked, and if they
have been placed on matting stretched across trestles, or on some other
raised platform, they are hand-turned, for about three weeks. They are
protectively covered from any night condensation or rain - the unwashed
process tends to be used in drier regions anyway - and the drying
process may be finished with hot air machines.
When only about 12 percent of their
moisture content remains, they are either stored in silos or are sent on
for final processing at a mill or factory, which may be under government
control. Here they undergo hulling, which in one operation removes all
of the dried skin, pulp, and parchment from the beans.
From this point the procedures are the
same for both washed and unwashed beans; they are polished, screened and
sorted, processes usually done with more sophisticated equipment,
including electronic sorting machines; and then graded and bagged. After
this the bags of green (still un-roasted) beans may go into storage or
they may be exported.