Coffee Processing

• Arabica trees normally produce fruit in the form of berries 8 to 15 mm in diameter, and Robusta produces berries approximately 10 mm in diameter. Robusta is regarded as inferior to Arabica coffee and is used mainly as a filler in instant coffee blends. Coffee berries are picked when they ripen to a bright deep red color.
• Within 24 hours of picking, remove all green unripe, and black overripe dry berries. Use a piece of wood to tamp the berries in a bucket until all seeds have been forced out from the skin. Fill the bucket with water and stir the skins and seeds. Pour away the skins before they settle. Repeat. Good coffee beans will not float in water.
• Place the coffee beans and water in a plastic bucket for 18 to 48 hours to ferment loose the insoluble mucilage around the parchment layer When the beans gritty and not slipper. wash the beans in agitated water and drain. Repeat until the water becomes clear. Use a colander to catch the beans.
• Dry the beans for 5 to 30 days or in a dehydrator at 40C for three days until the beans feel dry and brittle. The parchement should easily rub off. Store the beans in an air-tight container for two weeks to distribute the moisture.
• Place the beans in a food processor with plastic blades to loosen the parchment. Use a hair dryer to blow away the parchment.
• Roast the beans in large baking dishes in the oven. Spread the beans thinly and stir frequently to prevent burning and to give an even roast. As a rough guide, a, single layer of beans will roast in 12 minutes at 230-250°C, while beans at a depth of 25 mm may take 30 minutes at this temperature.
• Light brown beans (a light roast) will have a weaker flavour than brown/black beans (a dark roast). Adequately roasted beans should crack easily between the fingers. Cool with a fan to stop the cooking process.
• Store roasted beans in an air-tight container in the refrigerator and grind the needed amount just before use.
• Don't let coffee stand after brewing. Over-brewing destroys the flavour. The water need not be boiling, but just short of a boil.