Rwanda Coffee Grades

A two-tier system

Rwandan export Arabica is overwhelmingly fully washed and is separated at the dry mill into a tight top class and a wider second class. Grade 1 is prepared to the closest defect and screen standard, normally screen 15 and above. Grade 2 carries a wider defect allowance and includes smaller separations, typically in the screen 14–15 range.

That is genuinely most of the system. There is no equivalent of Kenya’s E/AA/AB/PB/C/TT/T ladder, and no cup component of the kind Ethiopia’s classification carries.

Why screen is specified separately

With only two grades doing the work that seven or eight do elsewhere, the grade cannot express size closely. Two Grade 1 parcels from different stations can differ noticeably in bean size, and a roaster running tight profiles will feel that difference.

The practical convention that has emerged is to contract on grade plus screen — "Grade 1, screen 16+" — rather than on grade alone. It costs nothing to write and removes the most common source of disappointment on arrival. See screen sizes for what the numbers mean.

The potato defect

No honest account of Rwandan and Burundian coffee omits the potato defect. A small number of beans in an otherwise sound lot can carry a pronounced raw-potato aroma and taste, caused by bacterial damage associated with antestia bug feeding. A single affected bean can taint a whole cup or a whole brew.

It is important to be accurate about what this does and does not mean. It is not a quality grade issue and it is not visible in the green — it cannot be screened or colour-sorted out reliably, because affected beans look normal. It appears at the cup, it is intermittent, and it affects a small fraction of beans when it occurs at all.

• Station management matters more than grade. Stations that manage antestia pressure in the field and sort aggressively at the table see it far less.
• Cup more cups than usual. Because it is intermittent, a single cup of a sample can miss it entirely. Cupping five cups rather than three is normal practice for these origins.
• Write it into the contract. Agree explicitly how the parcel is assessed and what happens if incidence exceeds what was accepted at sample stage.
• Do not treat it as disqualifying. Rwanda and Burundi produce some of the cleanest, sweetest washed Arabica in the region. The defect is a known, managed risk, not a reason to avoid the origins.

Traceability

Rwanda has a dense network of washing stations serving smallholders with very small plots, which makes the station the natural unit of traceability. Many stations can report by delivery period, and some by the collection site or sector feeding them. See traceability for what each level can be evidenced with.