El Monarca Coffee Classifier

Sizing or Grading

The coffee bean is now clean, the processes described in the foregoing having removed the outer skin, the saccharine pulp, the parchment, and the silver skin. This is the end of the cleaning operations; but there are two more steps to be taken before the coffee is ready for the trade of the world—sizing and hand-sorting. These two operations are of great importance; since on them depends, to a large extent, the price the coffee will bring in the market.

Old rope-drive transmission on Finca Ona.

Hydro-electric power plant on Finca Ona.

Hydro-Electric Installation on a Guatemala Finca

Sizing, or grading by sizes, is done in modern commercial practise by machines that automatically separate and distribute the different beans according to size and form. In principle, the beans are carried across a series of sieves, each with perforations varying in size from the others; the beans passing through the holes of corresponding sizes. The majority of the machines are constructed to separate the beans into five or more grades, the principal grades being triage, third flats, second flats, first flats, and first and second peaberries. Some are designed to handle "elephant" and "mother" sizes. The grades have local nomenclature in the various countries.

After grading, the coffee is picked over by hand to remove the faulty and discolored beans that it is almost impossible to remove thoroughly by machine. The higher grades of coffee are often double-picked; that is, picked over twice. When this is done on a large scale, the beans are generally placed on a belt, or platform, that moves at a regulated speed before a line of women and children, who pick out the undesirable beans as they pass on the moving belt. There are small machines of this type built for one person, who operates the belt mechanism by means of a treadle.

Preparation in the Leading Countries

The foregoing description tells in general terms the story of the most approved methods of harvesting, shelling, and cleaning the coffee beans. The following paragraphs will describe those features of the processes that are peculiar to the more important large producing countries and that differ in details or in essentials from the methods just outlined.