
Source: Wikipedia
Specifically – the process of washed coffee involves
- Picking ripe coffee cherries and delivering them to the washing station (6pm onwards)
- De-pulping and washing coffee at the mill, with good quality coffee cherries separated from defects using the water floatation method
- Via channels, the pulped coffee is then lead to their respective fermentation tanks
- After the tanks are full, the coffee is covered with water and fermented for 36-48 hours (depending on temperature) to remove the sugars from its parchment coat (refer to image above)
- After fermentation, the coffee is drained from the tanks and lead to the washing channel and manually washed using wood sticks
- From the washing channel, the coffee is soaked for a further 12 hours
- After the 12 hours, the water is drained and moved to a drying bed and spread across to a maximum thickness of 3 cms
- The coffee is sundried for approximately 7-9 days and constantly ventilated until the moisture is reduced to 9.5 – 11.5% —During this period – the coffee is raked and defective/broken coffee beans are picked by hand
- After this, the dried coffee is moved to the warehouse and ready for market
- To preserve their quality, the coffee beans remain in their parchment and is removed just before export
Many thanks to Beti Berhanu of Dumerso Coffee for consultation and explanation on this process.