The Culture of Coffee Processing

Ever wonder what happens to the beans after they are harvested?


Read on...

After being harvested, the coffee beans must then be processed either by dry-process, wet-process, or a semi-dry method. In the dry-process, the coffee beans dry while they are still in the cherry. This produces a coffee heavy in body - sweet, smooth and complex. Wet-processing is a new method which removes the four layers surrounding the coffee bean, resulting in a coffee that is cleaner, brighter, and fruitier.

Dry Process

The Dry Process is the oldest and the more traditional method of coffee processing in which coffee cherries are cleaned then spread out in the sun to dry on tables or in thin layers on patios. Workers constantly rake and turn the cherries by hand until the pulp dries. During this process the cherries turn brown. It may take up to 4 weeks before the cherries are dried to the optimum moisture content, depending on the weather conditions. Larger plantations sometimes use machine-drying to speed up the process after the coffee has been pre-dried in the sun for a few days.

Coffee Drying Racks

The drying operation is the most important stage of the process, since it affects the final quality of the green coffee. A coffee that has been overdried will become brittle and produce too many broken beans during hulling (broken beans are considered defective beans). Coffee that has not been dried sufficiently will be too moist and prone to rapid deterioration caused by the attack of fungi and bacteria.

Once dried, the fruit is ready for hulling. During the hulling process the fruits are placed in rotating drums containing blades that break the hull, releasing the coffee beans. Next, the beans are sorted according to size, density, color, and shape.

The dry method is used for about 95% of the Arabica coffee produced in Brazil, most of the coffees produced in Ethiopia, Haiti, and Paraguay, as well as for some Arabicas produced in India and Ecuador. Most Robusta beans are processed by this method. The dry method is not practical, however, in rainy regions, where the humidity of the atmosphere is too high, or where it rains frequently during harvesting. 


Wet Process


In the wet process, the coffee cherries are immersed in water to remove the over ripe or 

Wet Process

under ripe fruit. Bad or unripe fruit will float, and the good fruit sinks. Next the skin of the cherry - and some of the pulp - is removed by pressing the fruit – in water – through a screen. The remaining bean will still have a lot of pulp that needs to be removed. Fermentation is used to separate the coffee bean from the pulp. In machine-assisted wet processing, the machine scrubs off the pulp. After soaking in water for several days, the resulting pulp is removed, and the beans are then sun-dried on cement or mahogany patios for up to 6 weeks. Workers continue to rake the coffee during the day and move the beans into covered buildings during the night until the beans have dried thoroughly.

Semi-dry process

In this third process the coffee cherry passes through a wet screen and is then sun-dried without going through fermentation or through scrubbing.


Grading and Sorting the Beans

Machine sorting

After the beans have dried they are sorted and graded, either by machine or by hand. Coffee beans may be polished to remove any remaining chaff.

Coffee Sacks

After sorting and grading, beans are bagged and stored, waiting for the next stage of their journey.  








NEXT: Decaffeinating the Coffee Beans


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