Natural-processing, also known as dry-processing or sun-dried method (unwashed), is a traditional way of processing coffee. After harvesting cherries from the coffee trees, they are submerged in water to remove impurities and immature fruits.
The cherries are then spread out under the sun to dry. Depending on the farm, each farm does it differently: some use brick patios while some use raised beds. To prevent the fruits from spoiling, the cherries are turned regularly throughout the day and covered at night to protect them from the rain. This process can take up to anywhere from 3-6 weeks. During this period, the beans are fermented in the cherries.
After the cherries are dried, the seed will be separated from the skin and dried fruit flesh mechanically. What is left on the coffee beans then, will be a thin layer of skin known as the parchment skin; this skin will be removed through the last step which is also known as hulling. Thereafter, the coffee green beans are stored away to be rested.
This conventional method of coffee processing is common in regions like Ethiopia and some parts of Brazil. This process adds depths to the coffee’s flavours in terms of fruitiness and sweetness. Common flavour notes are berries and chocolate.