Methods of Drying
Most small coffee growers in Colombia and around the world dry their coffee in the sun. In countries like Colombia, farmers use structures with plastic roofs, called parabolic beds, to protect the beans from rain during the drying process. Farmers in drier regions, like Central America, typically dry their beans on concrete patios in open air.
Sun drying promotes quality, as the beans dry at lower temperatures and with pauses at night. This allows the bean to contract in a slow and controlled manner, losing around 50% of its size from wet to dry. If contraction occurs too rapidly, the cell walls of the bean can be broken and its aromatic components lost, affecting the quality of the end product.
Mechanical silos are another popular method of drying coffee, used primarily by medium and large producers.
Although there are several methods of silo drying, they all work based on the same principle: the silo is filled with hot air, drying out the beans’ moisture. Silos usually run between 45-60 degrees Celsius, and can dry coffee in less than 36 hours.
Although they will never be quite as beneficial as natural heat from the sun, silos can successfully dry beans without damaging them, provided that a low temperature is maintained. However, most silos are operated at scorchingly high temperatures, damaging the structure of the beans, which contract and lose moisture too rapidly.