About This Coffee
Kanzu washing station is located in the Nyamasheke district of Rwanda’s Western province. When the views are clear from the top of the ridge above the washing stations you can see all the way down to Lake Kivu to the west, which stretches the length of Rwanda’s border with the Democratic Republic of the Congo. Kanzu is a jewel of a place — organized and well-run, set against green hills of coffee, cassava, sweet potato, sugar cane, bananas, and beans at 1900 masl. Kanzu employs 50 local men and women during the harvest season. From start to finish, harvest in Rwanda runs about 4-5 months from March to July. Lots are separated by each outturn throughout the season.
After arriving at the washing station, cherry is floated and pulped, using a McKinnon disc pulper. The coffee in parchment then undergoes a dry fermentation for 16-18 hours before the remaining mucilage is washed off, followed by soaking. This typically takes up to 18 hours before the coffee is dried on raised beds with a mesh bottom, allowing for air circulation. The wastewater from the processing is treated with Effective microorganisms (EMTechnologiesTM) to secure the local water resources for the nearby community.
Very few coffee-producing countries have received the kind of focused aid that Rwanda has seen since the end of the genocide in 1994. Beginning in 2001 with the PEARL Project, and continuing with SPREAD, which ended in 2012, the Rwandese coffee industry was the focus of a series of collaborative development projects designed to rebuild the agricultural sector, mainly coffee & cassava, after the devastation of genocide & civil war. PEARL and SPREAD were funded by USAID and U.S. universities and led by Dr. Tim Schilling. By building washing stations, forming coops, and training agronomists, cuppers and quality control personnel, the programs helped to elevate Rwandese coffee to new heights, giving farmers access to specialty coffee markets and prices.
In 2012, Dormans took over Kanzu washing station and spent the intervening years making investments in infrastructure, training farmers on agronomic best practices, and improving quality control.
History of Coffee In Rwanda
The commercialization of coffee came about gradually in Rwanda and coffee was always produced on smallholder farms. Independence brought some improvement to the coffee infrastructure as the government established more modern and centralizing processing. But this meant the government set the price they would pay for coffee and farmers had no other options. There was no focus on quality because there was no incentive whatsoever. Despite much of the coffee being Bourbon, there was no sorting or grading so all the coffee was commercial grade. Rwanda exported 642,000 bags of coffee in 1993 and 447,000 in 1994. Then, as something of a stark reminder of the genocide, Rwanda exported a mere 22,000 bags in 1995. Today, Rwanda exports only 43% of what it did in 1993, but current exports represent much greater value because for the last 20 years the focus has been on quality rather than quantity, supported by various initiatives of the Rwandan government and international NGOs.
Growing Coffee In Rwanda
Rwanda’s ideal growing conditions are no longer wasted on poor processing. New washing stations have opened in all coffee growing regions, innovative cupping labs that arrive built into shipping containers, and cooperatives have been established. The vast majority of Rwanda's smallholder farmers grow high-quality Bourbon, well-suited to the high altitudes and volcanic soil of the region. For the last 10 years, Rwandan specialty coffees consistently rank among the finest in the world.
A Quick Note about 'Potato Defect', which can occur in coffees from Rwanda, Burundi, DR Congo, and Uganda
Potato Defect, or 'Potato Taste Defect' (PTD) is caused by a chemical called 2-Isopropyl 3-methoxy pyrazine (IPMP). In its strongest instances, this potato smell can be apparent in the air at the farm, in the green coffee including the cherry and parchment, as well as the roasted and brewed product. While there are ongoing, intensive efforts at the farm level to reduce the number of PTD incidences, there is currently no way to sort out the defect in the green or roasted coffee in a scalable manner.
For the specialty coffee industry in the regions affected by PTD, this defect has caused seemingly insurmountable issues at the farm level with direct consequences on the amount roasters purchase from affected regions as well as the selling power of area producers. Agronomists and biologists have proposed many theories and conducted numerous studies about the possible causes of Potato Taste Defect beginning as early as the 1950s, but currently there are no proven solutions to significantly eradicate the rate of defect.
Identifying Potato Taste Defect
There are very low, if any, visual identifiers that correlate to PTD defective seeds (or coffee beans). In fact, most defective seeds look perfectly normal to the human eye and show no visible insect damage or UV fluorescence. Therefore, unlike other defects, there is no “preventative maintenance” in processing or sorting methodologies that the producer can do to ensure a highly reduced rate of PTD.
PTD seems to be a defect solely detectable via gustation and olfaction. We have done research to better understand the defect occurrence rate in the coffees we buy, and are sharing our recommended protocols to avoid tasting the defect when brewing.
How Prevalent Is Potato Taste Defect?
In our research tracking PTD, the average occurrence rate of this defect is 1 in approximately 1550 grams in the coffees we buy. This means in every 3.3 pounds or so, the likelihood of hitting one PTD coffee bean is fairly high. It also means that the chances of experiencing potato defect in a 12 oz bag are low. Of course, there is a large element of randomness involved in this—that is just the nature of the beast.
In whole-bean coffee, there is no issue with transference. For example, if you open a bag and it smells of potato, the whole bag is not tainted. It is more than likely one defective coffee bean that simply smells very strong.
There is no known toxicity in the defect itself, and it is safe to consume, should you encounter it once brewed. However, since one defective bean can affect the taste of the resulting brew, we are sharing our recommended steps to take to avoid tasting potato.
Suggested Protocol To Avoid Tasting Potato
- When preparing to brew coffees from these regions, be sure to diligently smell the ground coffee before brewing.
- Grind your coffee in small amounts instead of grinding the whole bag at once. For home brewing, we recommend grinding <30 grams at a time. For batch brewing, we recommend grinding 100 grams at a time.
- If you only smell delicious coffee, continue brewing and enjoying these incredible coffees!
- If you are not sure, and you think you might be smelling potato, well, it is probably because you learned about PTD so your brain is telling you it is there. It might not be!
What To Do If You Smell Potato
If you smell raw potato (you’ll know!) in the grounds before brewing:
- Compost the grounds
- Purge the grinder of any remaining chaff/fines
- If possible, grind through approximately 30g of coffee that is guaranteed to not have PTD (such as a coffee from Guatemala, Colombia, etc.) as to prevent transference to the next batch of coffee
Region: Karambi, Nyamasheke, Western Province
Farm: Various Smallholders
Elevation: 1800-2100 MASL
Tasting notes: Sweet, bright, and punchy with lemon drop, bing cherry, and sweet tarts.