RWAMATAMU, Mbare Fully Washed

This coffee was processed at Rwamatamu's Mbare washing station in Muhanga, Southern Province. Upon arrival, the cherries are hand-sorted before being pulped and fermented in water for 12–48 hours. During fermentation, the cherry's mucilage breaks down. Once complete, the coffee is washed clean and spread on raised beds to dry for 21–22 days, depending on the weather. Finally, it's transported to milling facilities in Kigali, where it's de-hulled, polished, and graded.

Rwamatamu is a family-owned coffee producer established in 2015 by husband-and-wife team Rutaganda Gaston and Mukantwaza Laeticia.

Community is central to Rwamatamu's work. The team has built strong relationships with farmers in Nyamasheke and Mbare, and runs community groups in both locations.

In Nyamasheke, the Women's Cooperative provides local women with land, seedlings, and training for coffee production. The women cultivate and sell their coffee back to Rwamatamu, creating an alternative income source beyond seasonal employment and fostering long-term financial stability.

In Mbare, a Youth Association runs a similar project for locals aged 18–35, encouraging younger generations to develop interest and skills in coffee farming.

Bourbon is one of the most culturally and genetically significant varieties of Arabica coffee in the world. This tall variety is characterized by relatively low production and susceptibility to major diseases. However, it produces excellent cup quality when grown at high altitudes.

The first Bourbon plantation dates back to 1715 when the variety was introduced from Yemen to Bourbon Island, now known as La Réunion. Bourbon traces its origins to a broad group of C. arabica specimens that developed naturally and is still cultivated in Central America today.

Depending on the sub-group, Bourbon coffee can produce red, yellow, or orange-coloured cherries. The plant's shoots initially grow upwards at a 45° angle to the stem, and the stems are sturdy. Young leaves are green, and the plants generally have broader leaves and rounder fruit and seeds than Typica and its descendants.

The washed process was designed to minimize the risk of off-flavours caused by uncontrolled fermentation during the natural process. Cherries are typically sorted using a flotation tank, where under-ripe or defective fruits float to the top and can be removed. The remaining cherries are then pulped and left in a tank to ferment until the sticky fruit mucilage is soft enough to be washed off the parchment—a paper-like layer surrounding the seed.

The design and cleanliness of the tanks used for fermentation are crucial, and the type, degree and speed of microbial activity depends on various factors. These include the amount of fruit remaining, the presence of bacteria and yeasts, whether the tank is filled with water, and the environmental conditions.

Once the mucilage has sufficiently degraded, it's washed away with water. The remaining parchment coffee, as it's commonly called, is then dried until it reaches a safe moisture content. The bacteria-rich and sugary water used in the process must be treated carefully, as it can cause algae blooms if it enters streams and rivers.

In situations where large amounts of coffee are processed in bulk, such as in Ethiopia, some operations have found it economical to use a mechanical demucilager. This device removes all the fruit from the parchment with minimal water, bypassing the fermentation stage entirely. However, some believe this leads to a reduction in cup quality, as many flavour precursors are created through fermentation.