Havesting the coffee
Each year coffee is normally harvested during the dry season, when the coffee cherries are bright red, glossy and firm enough to be harvested. Ripe cherries can be picked by hand, stripped from the tree with both unripe and overripe coffee beans or collected using a harvesting machine.
The three processes are known as careful picking, stripping and mechanical harvesting, respectively.
To maximize the amount of coffee harvested it is necessary to selectively pick the ripe beans from the tree by hand and leave the unripe beans behind to be harvested at a later time.
In Brazil, harvesting the coffee beans from the same tree several times is more expensive than separating and discarding the unripe or overripe cherries, therefore, Brazil harvests coffee using the stripping method. When 75% of the crop is completely ripe the stripping method is feasible and cost effective due to the uniform maturation of Brazilian gourmet coffee. The stripping method uses a comb to brush the trees. Small rakes or poles are used to bring down the cherries to earth.
The third process is mechanical harvesting. If the terrain allows, harvesting can be done with special automatic machines. One method is to use a vibrator, which is fixed to the trunk of the tree. It shakes the ripe cherries loose so that they fall on the ground and then can be easily picked.
The other mechanized harvesting tools are rotating brushes connected to the side of tractors. Using this process, however, damages the tree ripping off the green cherries, flowers and leaves at the same time. This method is also expensive as it requires hand picking the cherries after they fall. Unlike most fruits, coffee has little ripening leeway after it is picked.
Deterioration begins immediately after the cherry is off the tree as the sugars begin to convert into starches. This naturally occurring process leads to rotting. Therefore coffee should be processed within ten hours of picking it.