Materials and methods
Coffee processing
On-farm coffee processing consists of several simple steps to separate and clean the valuable coffee bean from its hull. The process at FEV is similar to small-scale operations throughout Nicaragua. The coffee harvesting season corresponds to the dry season in the Nicaraguan highlands from December through February.
The process begins by receiving cherries measured by volume. FEV employs 30 pickers, primarily women from neighboring communities, during peak harvest. The beans are dumped into plastic tubs of water where low quality beans float to the top and are discarded. The rinsed beans are then taken to the depulper hopper where the seeds are depulped or mechanically separated from the fruit. The separation is not perfect and some fruit remains attached to the seed. The depulped seeds then ferment for 24 to 48 hours in holding tanks, loosening any remaining fruit and allowing the residual fruit juice to drain out. This juice is referred to as sweet water or agua miel in Spanish. Sweet water is commonly discharged into surface waters resulting in eutrophication and poor water quality if unmanaged ( Ferrell and Cockerill, 2011 and Flysjö and Ohlsson, 2006).
Next, fresh water is used to wash the seeds and float out the remaining fruit and lower quality beans. After washing, the coffee is dried on-site using simple screen racks to approximately 40% moisture content. While drying, the beans are sorted into three grades based on size, color and uniformity. Upon sufficient drying, the beans are transported to a commercial drying facility where the moisture content is reduced to 10 to 12%, ready for packaging and export. This process flow is shown in Fig. 2.