Rwanda is one of my favorite coffee origins. The people are remarkable, the coffees are exceptional, and the country is beautiful.
Agriculture was a driving force in Rwanda’s recovery from the country’s horrific genocide in the 1990s, and coffee – particularly specialty coffee – has played a significant role in that regard. Working side-by-side, coffee cuppers and aid workers helped train and educate an entire generation of Rwandans who are now coffee business owners or occupy senior roles in export offices and quality labs across the country.
The coffee washing station is of critical importance in Rwanda. Nearly no large estates exist; instead smallholders will sell cherry outright (the government sets a minimum price) to the closest washing station. Because of the high population density even out in the countryside, and the good price on the global market, turf wars between washing stations can emerge. Some will send trucks out to local farming communities to “poach” cherry from other stations.
Regardless, it’s the washing stations that get to control the quality of coffee cherry, starting with presorting and flotation, through pulping and drying and parchment sorting and storage. This particularly clean example of Rwandan coffee comes from the southwest of the country: Cyanika town in the Nyamagabe district. The Karambi washing station was established in 2003, and sources coffee from over 700 nearby farming families. Coffee processed at Karambi took 6th place in the 2015 Cup of Excellence.
This cleanly prepped Southern Rwanda comes to us with a slightly higher than average density, a low moisture content and water activity reading, and a wide screen size distribution. It’s not uncommon to find Rwandan coffee a little smaller in size than average. The low moisture figures are an encouraging sign in coffees from this area of the world – Rwandan coffee harvests during the rainy season, so drying parchment is under constant threat of seasonal rains. Washing station employees must constantly be on the lookout for rainclouds and be ready at moment’s notice to cover the drying coffee with tarps.
Most Rwandan coffee farmers are still using older local Bourbon varieties distributed as long ago as the 1950s. The two most common of these are called Mbirizi and Jackson, and can be found widely distributed in Burundi as well. Rwandan farmers have access to fertilizer distribution through a government-authorized agency, but good agricultural training can sometimes be difficult to find in the countryside. Despite lower than average per-hectare yields, these coffee varieties tend to produce high sensory quality.
After a bitter fight with a dreaded sensory defect known as “potato,” the last several years, we’re seeing decreasing frequency of this troublesome hiccup in quality. Part of the problem, of course, is that the defect is practically undetectable until roasted, so it’s difficult to eliminate at the farm or washing station. However, pre-processing cherry flotation at the wet mill and extensive hand-sorting of drying parchment seem to be helping.
I jumped at the opportunity to do some roasting on the Ikawa this week. I took one of Jen’s successful profiles from previous sessions, and created one of my own that used differing airflow and temperature settings but finished in the same time. This allowed us to compare two very different approaches quickly as a preview before Jen took larger batches to the Probatino.
You can see the airflow represented on the chart: Jen’s roasts follow a more traditional Ikawa profile with an evenly paced rate of rise (green) and an airflow setting that decreases slowly towards the end of the roast (blue). Her roast employs about a 1 minute post crack development time that tends to result in a nice, even roast with a balance of sugar browning and Maillard reaction flavors.
My profile used a lower charge temperature, and a high initial airflow. I then drop the airflow to increase heat quickly through the Maillard reaction, and raise the airflow at the end of the roast to abate smoke and slow first crack. My profile typically results in a thinner body with higher acidity than Jen’s.
For this Nyamagabe coffee, Jen’s roast style tasted like root beer, raisins, and apple pie, while mine tasted like papaya, cane sugar, and fresh baked bread.
In this week’s analysis I wanted to translate the Ikawa roasts to the Probatino to see if we would get the same results. Unfortunately, I could only replicate the roast profiles and not the airflow because the Probatino does not have that functionality. There is one damper in the stack to the chaff cyclone held in place by a wingnut. It is just too far away from the front of the roaster to safely adjust during a roast.
With that in mind, I gave Probatino (1) a high dose of heat just after turnaround and quickly backed off after yellowing. This gave the curve a more gentle and gradual rise. As I neared first crack, it was necessary to add more heat. In Probatino (2) I delayed heat application until necessary or when I noticed that I would lose momentum in the roast due to a rapidly decreasing rate of change. My aim was to have a steeper curve in the profile which would lengthen the drying time and decrease the Maillard stage. For both roasts, I tried my best to have them finish the same with the same post crack development times and end temperature. Interesting to note that in all three coffees this week, Probatino (1) had a few pre first crack pops, likely due to the quick punch of heat and screen size variance.
Although Probatino (2) had a longer roast time and slightly higher end temperature, it was lighter on the Colortrack which we can attribute to the reduced Maillard time. While darker in color, the organic acids in Probatino (1) were bright and citric and Probatino (2) had more developed sugar browning flavors. These profiles did not correlate with the Ikawa flavor profiles which could be related to the differing airflow strategies that Chris mentions in the Ikawa analysis.
Unless otherwise noted, I follow a set standard of operations for all my Behmor roasts. Generally, I’ll use the 1lb setting, manual mode (P5), full power, and high drum speed until crack. Read my original post and stats here.
During my tenure at Royal, Rwandan coffees have been a rare sight at the cupping table when compared to some other major origins. I learned to love these coffees while working at Blue Bottle in Oakland, and I haven’t changed my mind since. Rwandan coffee has some amazingly unique flavors, and this coffee is not here to provide any evidence to the contrary.
As you can see above through Jen and Chris’ roasts, there is plenty of nuance to work with here.
Pay close attention as this coffee nears crack. The beginnings of first crack were very soft, but continued to pick up in volume and pace after about 20 seconds. This gives you a bit of time to lower heat immediately before first crack, if you’re paying close attention. This coffee retains plenty momentum to finish developing with lower heat application.
I ended up letting this coffee develop for just a tad longer than I would have liked, but the result at the cupping table was a complex and sweet cup with a few deeper sugary notes, and very slight tamarind and root-beer-spicy finish. Pulling back heat application as soon as you hear those first puffs of first crack would likely be the best way to go with this coffee!
Rather than brew every roast once, this week I chose to take our favorite Probatino roast and brew it in multiple extractions. Focussing on one brew allowed me to explore the potential of that particular roast and brew two extremely different recipes to see how the coffee changed.
I knew we weren’t exploring the full potential of our coffees by brewing each roast only once. By the time the Brew Analysis portion of our release schedule begins, the Crown team has cupped these coffees together at least 3 times, sometimes more, at many different roast levels. I usually have a good idea of what I’m working with by the time we get to the brewing portion of our projects. And yet, I was sure that exploring one roast more profoundly was sure to provide interesting results.
The Cyanika Karambi really proved my point; neither of my brews were ideal – in fact they were both rather extreme. One hovered at the over extracted/bitter end of the extraction spectrum while the other sat just inside desired parameters, but on the weak/under extracted side of things. And yet, both were really tasty.
The 1:15 ratio brew (Probat 2A) provided orange zest, apple, and floral brightness balanced by molasses, brown sugar and toffee. Meanwhile, the 1:18 ratio brew (Probat 2B) created honey and raisin sweetness, elegant vanilla, clean lime and marmalade acidity with plenty of caramel or turbinado sugar notes.
On paper, neither of these brews looked very desirable. And yet, this coffee is such that it can offer a wide variety of flavors and levels of complexity without betraying many unpleasant notes. This is an incredible feat, and speaks to the dedication to quality of the folks at Karambi washing station as well as the producers themselves.
As a barista serving this coffee, I might have found it surprisingly easy to dial to my traditional brew specs and would have left it at that. Getting to explore the boundaries of brewing potential may be a perk of this job, but in this case it proved incredibly informative. As always, experimentation is the best way to learn.