Rwanda has one of the most interesting East African coffee histories
It is a place where the production of high-quality coffee is inextricably linked to the rising spirit of a population after the tragic genocidal civil war of the 1990s. Known as the "Land of a Thousand Hills," many of them are cultivated in high-grown coffee between 1700 and 2000 meters above sea level (MASL). Rwanda coffee can be world class. They often have clean bright flavors rivaling the best Central America coffees, more balance than Kenyas, attractive fruited sweetness, floral characteristics, and with a tea-like finish.
It is believed that coffee was introduced in Rwanda in 1904 by German missionaries. Around 1930, a considerable interest in coffee developed as it was the sole revenue-generating commodity for rural families. Not long ago, Rwandan coffee was rarely seen in the United States at all. The strong relationship with Belgium (the former colonizer of the country) made it a near exclusive buyer for the low-grade commercial coffee produced in Rwanda, as well as a lone trader from London.
Coffee is grown in many sectors, but most coffee comes from the South and Western districts. Many farms are perched at altitudes ranging from 1700 - 2000 MASL. Coffee is grown all along Lake Kivu, from the northern area of Gisenyi to the central areas of Kibuye and Nyamasheke, down to Cyangugu. In the South there is a lot of production in the vicinity of Butare. The North has more limited coffee growing, with much in Rulindo district north of the capital Kigali. And the East produces a decent amount of volume too, but much of it is grown at lower altitudes of around 1300 meters.
The government encouraged (actually, they mandated) high-volume, crudely-processed coffee production. Even with this low grade coffee production, coffee played a considerable role in the economic development of the country because it was one of the few cash crops. But with the collapse of world coffee prices at the international market level, the push to export low-grade arabica made less and less sense. Historically, Rwanda had been the 9th largest producer of arabica in Africa, with 500,000 small farms averaging less than 1 hectare each. Farms have usually not been measured in land area: being so small, they were measured in number of trees. The average is 165 trees per farmer, miniscule compared to other nations! The season in Rwanda harvest is roughly March - July, with arrivals in the US between June - September.
Rwanda coffee was traditionally processed by each small producer, and there was only one true wet-process coffee mill (called a washing station here) in the country. This home-processed coffee still accounts for the majority of production, and is called "ordinary" or "semi-washed" since most of it doesn't have complete fermentation to remove all the fruit mucilage from the parchment layer of coffee. It is estimated that 60 to 70% of current production goes into semi-washed blends. This type of processing isn't inherently bad, but when you mix it all together, well-processed batches with poorly-picked and processed ones result in the lowest common denominator for cup quality. As I ask producers - "what happens when you mix a glass of clean spring water with a glass of muddy river water? Two bad glasses of water"!
This type of low-grade production never returned much to the farmers, but there was so little export production of any kind from Rwanda, it had an outsized significance to the country and to the individual coffee producer.
Then the genocide occurred, and how any society returns to a "normal" life after the tragedy of monumental scale is difficult to imagine. But the recovery in Rwanda has occurred with an unflinching openness to the genocide. (A personal thought: I think much of the world stood by because awareness of Rwanda was low, and self-interest in Rwanda was low. What did Rwanda produce and export that the world cared about? Clinton said so much at the time, and in retrospect regretted it as did other world leaders on whose watch the massacre happened. I feel that interest in Rwanda, awareness of their products and the people, would make another tragedy difficult to ignore, and coffee is a "gateway to the world" in that sense.)
After the genocide, as the floodgates opened for assistance to the Rwandan population, revitalizing coffee production was made an important goal. To do this, organizations like the PEARL project and SPREAD standardized and trained farmers and new cooperative washing stations in traditional techniques of coffee production based on other East African countries. Burundi in particular offered a good model for production.
From the farm through to the washing station, coffee production in Rwanda is quite ideal for a small-holder farmer type system. The original ways of planting and pruning the tree are well done, with the already-mentioned varietal selection (Bourbons-types, generally), plant spacing, mulching for water-retention, organic material input and weed control, light shading of coffee with trees, and Kenya-type pruning techniques. The government (via their coffee board NAEB) distributes fertilizer to farmers at the wet mills. Bourbon types grown in Rwanda include these attractively named plants: POP3303/21; Jackson 2/1257; BM 139.
After the coffee is picked, the cherries are often floated in water to remove light beans. Pulping is often done with Kenya-type disc depulpers than include a grader for light and heavy beans. The light beans are taken out and go to a secondary huller and a separate low-grade fermentation tank, for B and C grade coffees. The heavy dense beans go to the fermentation tank for A grade beans, and these are eventually designated as A1, A2 and A3 qualities.
One of the best things in Rwanda processing is the fact that all the coffee goes to the "skin-drying tables". These are raised shaded beds where the wet parchment coffee is picked over to remove defects that are especially apparent in the still-wet parchment. In particular, the workers remove Antestia affected coffee, under-ripe beans, pulper-nicked coffee, fruit skins, or beans where the parchment was mistakenly removed and ffected by the ferment water in the tanks. (Remember, the purpose of fermenting coffee is not to affect flavor. It is to break down the fruit mucilage that clings to the parchment layer surrounding the bean. This skin keeps the ferment process, and broken-down mucilage fruit, away from the green bean. If a green bean comes into contact with the sticky ferment water, it will taste like ferment (think rotting fruit) and ruin the cup quality.)
This skin-drying phase not only allows an extra chance to remove defects, it slows down the initial drying of the parchment, which I feel increases cup quality. The coffee then goes out the the raised drying tables, where it takes 15-20 days (ideally) to reach a moisture level of 11% or so. In the heat of the day, the workers cover the coffee to prevent too-rapid drying under direct sun. The result with the best Rwanda coffee is a totally white-colored parchment coffee with no cracks from rapid drying. Why is this good for quality? Because this tiny parchment "shell", facilitates a safe drying environment, buffering it from the outside. It allows a slow and even loss of moisture, which results in less loss of organic compounds (good for cup flavor), and ultimately a green coffee that can be stored longer without degrading.
Challenges with Rwandan coffee
One of the challenges in Rwanda is the poor organic material content in the soil. Every small patch of land is cultivated in this country, and has been for many decades. The soil is depleted, and there isn't enough sources for new organic material to add back. Some level of chemical fertilization is needed, as well as returning every possible type of compost to the ground. The NGOs brought the California Red Worm here to introduce vermiculture as a source for improved compost, especially to break down the coffee pulp (the skin and outer layer of the fruit) created during processing.
Another great challenge is the dreaded "potato defect," so named because it smells like an old, sprouted potato in the cup. The problem is specific to the East African lake areas of Kivu, also found in Burundi and Congo coffees. This off-flavor is caused by a bacterial agent that enters the cherry skin and produces a pyrazine chemical toxin that binds to the forming green beans. The bacterial transmission is often brought into the fruit by the Antestia bug, a type of coffee berry borer insect that is attracted to sugars in the coffee fruit. But anything that pierces the cherry wall can allow the bacteria to enter and eventually release the the nasty pyrazine. Removing the affected beans is necessary to keep from getting a "potato" cup, but at this time, there is no mechanical way to identify them. The result is that, even with top coffees, an occasional cup will have this potato taste. It's tragic, given how good the coffee can be.
Another issue that is often overlooked is the business of the washing station. In years where the coffee market is high, there is usually a rush of investors building washing stations and buying coffee cherry, often without forethought as to how they will finance their purchases, sell the coffee (so they often overpay for cherry thinking there is a big payout on the other side), and the important relation between quality and price. Additionally, cooperatives can be poorly-managed, and in fact are often not "cooperatives" as we imagine them to be. They might be a group of some larger local farmers and a few people from Kigali, the capital, who have never farmed coffee in their lives. There might be 10 "coop members", but the farmers they buy cherry from are not actually members of the coop, nor allowed to be. With both these less-than-ideal scenarios, the problem for the farmer is that the market for their coffee cherries is not reliable. One year the station might operate, the next year it doesn't. They always have the option to process themselves and sell it as semi-washed, but the price is much lower.
For our part we have tried to seek out private and coop stations that are serious about the coffee business.
They need to understand it well, be from the area, and want to return something beneficial to the farmers they buy from. Some of our sources were supported by a good program run by the Technoserve NGO in Rwanda, and now receive support from the service providers born out of that effort.
Each year we make a few trips to Rwanda during the coffee season and have participated in the early competitions here, including the first-ever Rwanda Cup of Excellence competition in 2008, and again in 2010.