First Washing
After the pulp of the coffee cherries has been removed, coffee beans are deposited in tanks employed for fermentation. A controlled fermentation is required to separate the mucilage of the fruit from the coffee beans. Once optimum fermentation is achieved, coffee beans proceed to begin the washing process. For the next stage of the process, an independent water recycle circuit is employed. The amount of water employed in this stage is three thousand liters. This water is responsible for transporting the coffee beans from the fermentation tanks to the first separation channel, in which floaters are to be separated from sinkers. The same water is responsible of transporting all the high density coffee beans to a washing pump in which the beans are to be washed.
In addition, the same water is also responsible for conveying all the coffee that did not sink to where low quality coffee is to be processed separately. Once coffee is washed, it goes through a separation cascade where coffee is separated from the first washing water. Coffee goes to a sorting pipe, and wastewater returns, through closed circuit pipelines to the first washing-settling tank.
We consider this wastewater to be the richest (contaminated water) in pectin and bacteria, which are beneficial for coffee fermentation. That is why such water is introduced to the water employed in the de pulping process in the variable settling tank, as the same has lost volume since coffee pulp has absorbed it. Water absorbed through the pulp is slowly drained, and sent directly to the clarification tanks.
First washing water is employed every day, and replaced on a daily basis with clean water. In this process, water is re circulated yet not recycled. During the harvest of 2005-2006, 741,000 liters of water were employed in the washing process of coffee beans.