Introduction by Chris Kornman
This double washed Nyeri coffee is actually a blend of two peaberry selections from different, nearby washing stations, aka Factories, run by distinct cooperatives. Ruiruiru (I love saying this name!) is managed by Mathira North Farmers Cooperative Society, while Kiamaina operates under the Kiama Farmers Cooperative Society.
Peaberries are genetic flaws, typically making up no more than about 5% of an average harvest. Typical coffee seeds split during the early stages of growth inside the cherry, forming two so-called “flat beans.” Peaberry seeds never undergo the split, and thus are completely round.
Smallholders like those that contribute to Ruiruiru and Kiamaina tend to measure their plots by number of trees rather than acreage, averaging around 250 coffee plants per plot. Many are inter-cropping to improve the biodiversity of the region and the security of their harvest, planting banana, grevillea, and macadamia in addition to coffee. Kenya’s auction system elevates the value of exceptional coffees, and keeps the country’s coffee margins high, stable, and independent of the volatile C Market.
Like most Kenyan growing regions, coffee in Nyeri benefits from its equatorial location and two distinct annual rainy seasons, resulting in a main crop in the winter and a “fly” crop harvested in the summer. However, East Africa has been hard-hit by climate disruption in recent years, and Kenyan production is very low this year by comparison to last. Early predictions originally seemed to indicate a good year, but drought, irregular rains, and a frost in Othaya have cut yields for both main and fly crops.
Green Analysis by Chris Kornman
Peaberry coffees like this one tend to be both small in size and high in density. It’s not unusual to see a little wider distribution in screen size, as well, since peaberry isn’t so much a size designation as it is a distinctive shape. While often prized by roasters, particularly from Kenya and Tanzania, the size, shape, and density can cause some complications when roasting. Keep an eye on Jen’s notes for heat applications.
The lot is built on a blend of common Kenyan varieties. SL-28 and SL-34 are two of the most highly regarded varieties produced by Scott Laboratories in Kenya in the 1930s. Scott Labs no longer exists as such, but is now the National Agricultural Laboratories, a part of the larger Kenya Agricultural & Livestock Research Organization. Both varieties are Bourbon derivative cultivars, though from different lineages: SL-28 was developed from a drought-resistant variety originally cultivated in Tanganyika, a territory that makes up part of modern day Tanzania; it’s generally considered to be of the highest quality but is not very productive compared to other commercial Arabica varieties. SL-34 is a Kenyan mutation originally found near Kabete, and excels at lower elevations. Both of these SL variants exhibit bronze-tipped leaves on the newest growth.
Joining the classics are two relative newcomers. Ruiru-11 was developed in the mid-1980’s as the result of attempting to make an SL-28 more productive and resistant to Coffee Berry Disease and Leaf Rust by crossbreeding with varieties as disparate as Sudan Rume (for quality) and Catimor (for disease resistance), among others. In response to qualitative feedback, the Coffee Research Institute retraced the steps to creating Ruiru-11, attempting to improve cup quality without compromising disease resistance. Since 2010, the new variety called Batian has trickled into production, and early results are promising.
Roast Analysis by Jen Apodaca
Sometimes your machine is hotter than you think and it pays to be quick on your feet with a plan. When I started my second roast of this coffee, I wanted to lengthen the overall time and create some more sugar-browning notes in the profile. By keeping the same charge temperature and delaying my heat adjustment, I expected to lengthen my drying stage and/or my Maillard time. Instead, I saw little to no change in the curve and even a slight increase in pace. This leads me to believe that my drum was much hotter than I anticipated. As I raced through the drying stage and the Maillard stage, I turned the heat down a quarter tick until I heard first crack. During first crack I was afraid that I would stall. I did the unthinkable and turned my heat back up to 3 gas while the coffee was releasing most of its moisture. I was still able to create sugar browning flavors post first crack in a method I can only relate to a reverse sear when you cook a steak. On the cupping table this actually had a pleasant effect. Both roasts were vibrant and full of tropical juice flavors, but while roast one had a vegetal/tomato flavor in the mix, roast two was floral, sweet, and tart with no vegetal qualities.
Roast one: Blackberry, pineapple, sundried tomato, tart
Roast two: Cranberry, grapefruit, nectarine, rose, lavender
Behmor Analysis by Evan Gilman
For this coffee, I followed the parameters outlined in my earlier article (manual full power with the P5 setting, high drum speed) with no hiccups. I didn’t try anything too ambitious with this roast, but wanted to perform a slightly lighter roast than CJ1139, which turned out rather dark. I certainly got what I was after, maybe to the point of being a little too light.
Fans of a very light roast will enjoy my parameters below, but if you’re after more developed sugars, a bit more development time would bring out more jamminess in this coffee. All sorts of clean fruit notes made themselves known in this lighter roast: cranberry, orange, plum, watermelon. Our resident light roast lovers were enamored by it, but some of us at the table would have liked to see more development – a divisive roast!
Brew Analysis by Chris Kornman
Jen and I tasted this peaberry coffee as an afternoon coffee brewed in glass Kalita Wave. At a 1:16 ratio and a standard grind size, the coffee proved more soluble than I expected, yielding a very high TDS for both roasts.
Jen preferred the brew of the second roast, noting blackberry jam, juicy limeade, sweet green grape, and a creamy, custardy viscosity. My preference tended towards the first roast: bright grapefruit, pomegranate, and cherry notes accompanied a hibiscus flourish. The high extraction numbers didn’t seem to adversely affect our tasting experience all that much.