Dry Processing the Coffee Bean

Dry Processing the Cherry (Coffee Bean)

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.

Dry Processing

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.


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