Coffee beans start out as ripe coffee cherries which are harvested and processed various ways to remove the skin, pulp, and parchment. The dried parchment of coffee cherry seeds are removed to expose the two (sometimes one) “coffee beans”. If properly stored, unroasted coffee beans can stay alive for months, and may even germinate into new coffee plants if planted and watered.
The green beans are removed by one of three methods : Either the Dry process, wet process or semi-dry method.
In the dry process, ripe cherries are first dried in the sun, after which the dried skin, pulp, and parchment are removed from the bean (seed). The process takes about two weeks and the cherries must be raked while drying to avoid mildew. Dry processing produces coffees with less acidity and more body compared to the wet process. Dry processing is only done in growing regions with a naturally hot and dry climate. Brazil, Ethiopia, and Yemen produce most of the worlds dry processed coffees. Dry processed coffee is also called “unwashed”, or “natural”.
In the wet process, ripe cherries are first immersed in water where any floating cherries are removed as defective. The remaining cherries are then pressed by machine against a perforated surface, allowing only the seed, and some attached pulp, to pass through the holes. The remaining pulp is then removed by placing the beans into a fermentation tank to loosen the pulp before washing the pulp away with water. After the pulp is removed, the coffee beans are then dried to about ten to twelve percent moisture content, usually by a combination of sun drying and machine drying. Machine drying is common practice, especially in damp climates, to prevent mildew. Wet processed coffee is sometimes called washed coffee, in reference to the washing done to separate the pulp from the beans. Also called the wet method.
Semi Dry Process
In the semi dry process, coffee beans are pulped as in the wet process. The coffee beans with parchment and some mucilage still attached are then dried instead of the usual fermentation done in the wet process. After drying, the coffee beans are dehulled (separated from the parchment), sorted, and placed in burlap sacks for export. The semi-dry process is common in the islands of Sumatra and Sulawesi, and is sometimes used in Brazil.
After processing the coffee is then sorted and graded. Grade is generally used to indicate coffee bean size, which is associated with coffee quality. While there are many exceptions, coffee beans grown at higher elevations tend to be denser, larger, and have better flavor. The process of determining coffee bean size, or grading, is done by passing unroasted beans through perforated containers, or sieves. For example, Grade 18 beans, also called AA, will pass through a sieve with 18/64″ diameter holes, but are retained by the next smaller sieve with 16/64″ diameter holes. Traditionally, even grades were used for Arabicas (20, 18, 16, etc), and odd numbers were used for Robustas (17, 15, 13, etc). The method of grading coffee (classifying coffee quality) varies by country, and may include bean size, bean density, number of defects, growing altitude, taste, etc.
After grading the coffee is then packed and shipped to various locations. The coffee is now ready to be roasted. There are a number of different methods used to roast coffee. These roasting methods depend on quantity, resources and desired effect.
Once roasted the coffee is then blended according to a certain formula or recipe and then packaged.
For enquiries into the methods we used to roast our coffee and for info into details of the green beans which we use please contact us at http://www.aquaspresso.co.za/index.php/contact-us/