Introduction & Taste Analysis by Jen Apodaca
As sensory professionals, it is our job to use language to describe the flavors that we are experiencing and then determine whether those flavors are a positive or negative experience. What happens when a coffee does not follow a typical specialty coffee profile? In 2012, I was on my first international jury for Cup of Excellence and although I had participated in cuppings with international audiences before, it was during this week that I heard a few jurors use descriptors that I had not previously associated with specialty coffee in a positive light. On a particularly sweet coffee, another juror had used shrimp as a flavor descriptor. Sure, I had tasted coffees with a fishy process before, but this juror specifically referred to the sweetness of shrimp. It got me thinking about my limited flavor experience, and yes shrimp is sweet.
So where am I going with this? What I want to talk about is sweetness. Recently on the arrival table, we cupped a Tanzanian AAA coffee that had a complex sweetness like roasted nori. This was not the first time I had tasted a green sweetness in Tanzanian coffee. I wanted to know how this flavor would manifest itself in the cup over several different roasts. I often describe to new cuppers how sweetness can be influenced in roasting. From a light roast we can taste: cane sugar or raw brown sugar to a medium roast: chewy caramel or hard candy to a dark roast that can display a bitterness like toffee or the scorched sugar atop a creme brulee. So how would roasted nori translate as a lighter roast and as a darker roast? Would it be grassy or bitter with a small window of sweetness? Or would it translate into a spectrum of sweet green flavors?
In the diagram below we accumulated all of the tasting notes from every roast and every cupping and brew session. As you click through the charts notice how the flavors change from roast to roast. The roasts displayed go from light to dark with roast one being the lightest and roast four being the darkest.
Roast Analysis by Jen Apodaca
All four roasts were designed to end within 5 degrees of separation; Roast one at 402.5 °F, Roast two at 406.5 °F, Roast three at 410.6 °F, and Roast four at 415.3 °F. There is a small amount of difference prior to first crack, but most of this is operator error. The real difference between these roasts is in the post crack development. During Post Crack Development is where we see the main difference between these roasts, they are all close to 5 degrees apart in end temperature and 68 seconds apart in total roast time. This difference in end time and temperature makes a difference when we look at these coffees with a color analyzer.
Using the Colortrack I can look at the evenness of the roast by comparing a whole bean sample to the ground sample . Our lightest roast (roast one) is the shortest in total roast time and has the largest variance of Colortrack readings (4.88) between the internal and external color. At the cupping, roast one had the punchiest acidity and the least amount of sugar browning characteristics. The majority of the flavors were composed of citrus fruits and the herbal character consisted of fresh green flavors like sencha tea and basil. Although there were not too many sugar browning characteristics, there was still a syrupy body and a vanilla and butterscotch sweetness.
Likewise, our darkest roast (roast four) has the longest total roast time and has the least difference (2.38) between the internal and external color. Roast four, was mostly composed of sugar browning notes like dark chocolate, maple syrup, and condensed fruit flavors including some dry distillate flavors like juniper and violet. The only trace of citrus was a zesty grapefruit finish.
Roast two and roast three were the favorite of the group at the cupping table which is likely because they displayed the most balance of the unique flavors that this coffee has to offer. Roast two led with a complex acid structure with aromatic florals and sweet herbs with a huge creamy body like green tea ice cream. Roast three was the least vegetal of them all and had a more traditional specialty coffee flavor profile of juicy citrus and milk chocolate.
The green herbal nature of this coffee may not be for everyone, but there is no doubt that this is a sweet coffee. I recommend plotting a course around roast two and roast three for the best iteration. The key to a coffee with a lot to say is to find the right balance between the acid structure and sugar browning flavors and you will be rewarded with a lovely and intriguing flavor profile.
Brew Analysis by Colleen King
Upon initial cupping of this coffee, we noticed some savory, brine-like qualities in the form of nori and matcha. Intrigued, Jen roasted this coffee four different ways to explore the different forms of sweetness, and how they would affect these savory qualities. We brewed this coffee on a Bonavita to achieve a consistent brewing technique. All four roasts were very soluble, extracting over 22% and hitting an optimal 1.5 TDS without any trouble.
Roast one was the lightest in color tracking, had the highest acidity, and a relatively thin body. The savory qualities we experienced in cupping were muted, but we did note herbal quantities alongside the sweetness of graham cracker and lime. This roast performs best in a filtered method with a stirred bloom (quickly and aggressively) to ensure even extraction.
Roast two was our favorite, faring better as a filtered coffee than on the cupping table. This is a great example of the importance to both brew and cup production roasts for evaluation. This coffee was a little more developed, resulting in a creamy full bodied cup. We did experience some roasted vegetal undertones, which were offset of by the high sweetness notes of milk tea, caramel and finger lime.
Roast three was deemed most chuggable. We recommend this roast profile when serving customers sensitive to acidity, or alongside a full food menu. We noted lower perceived sweetness and acidity, but full bodied and syrupy qualities. Notes of rootbeer and powdered cocoa make this roast approachable, but not outstanding.
Roast four is the most developed and darkest roast. We recommend this roast profile when serving to customers new to specialty coffee. It should be noted that the aromatics were very grassy and herbal. The brew was a little drying, and had significantly more savory qualities like toasted rice, roasted green tea and juniper.
Background by Chris Kornman
Tanzania is a country of extremes. The continent’s highest peak (Mt. Kilimanjaro, at 5895 meters above sea level) and deepest trench (the floor of lake Tanganyika at 352 meters below sea level) are both located within the East African nation’s borders. Temperatures in the port city of Dar Es Salaam regularly reach triple digits, while snow never leaves some of the caps of the country’s mountains. The country once was held under colonialism first by the Germans, then the British – it wasn’t until 1961 that the Tanzanian people regained their independence.
Coffee, too, has its share of extremes in the country: the three main growing regions are each located in far reaches of the country: the northwest near the Rwanda/Burundi border, the northeast near the Kenyan border, and the Southern highlands near the Zambia/Malawi border each boast unique geography and coffee growing cultures. It is the latter that claims the largest production of the three, though the coffees from the country’s southern reaches are often an afterthought in American specialty, as the countryside is rugged (only within the last few years getting an airport in Mbeya and paved roads to the port) and the producers are mainly poor, loosely organized smallholders (as opposed to the larger, well-established estates near Arusha, for example).
This Crown Jewel is grown in the Ndugu Hills microregions west of Mbeya town. Farmers growing crops in Mbozi and nearby cities of Songwe, Vwawa, and Hasamba must battle high temperatures and drought during the dry season. The Ndugu Hill farmers group only built their washing station as recently as 2014.
Green Analysis by Chris Kornman
A true AAA, this coffee is huge! Just the 18 and up screen size to be found here. Its low density reading of 0.654 g/mL is likely a function, at least in part, of the large size. Solid moisture figures enhance the coffee’s shelf-stability.
Much of Southern Tanzania’s heirloom Bourbon cultivars are generations old, still producing coffee on family farms like those that contributed to the Ndugu Hills lot here. As a result, many producers struggle to fertilize and adequately combat pests, to which Bourbon tends to be less resistant. TaCRI, the nation’s agricultural research center, has developed many of its own varieties for distribution, but they’ve largely failed to make their way to the smallholder farms, and it’s hard to argue with the classic taste of heirloom seeds like those grown in Mbeya.