Exploring Processing with the Long Miles Coffee Project

By Evan Howe

The Long Miles Coffee Project, a family endeavor founded by Kristy and Ben Carlson, is one of the six producers that we refer to collectively as the Foundational Partnerships. In addition to working closely with the Long Miles team to source annual, larger-volume lots that we present as the Heza Foundational lot and the Burundi offering on the menu of our sister company Necessary Coffee, we also enjoy collaborating on additional microlots that find homes on Passenger’s Reserve and Education Lot menus. Thanks to the amazing support of the Long Miles team, we are excited to share the present collection of six Education Lots that explore the impact of processing in fascinating ways and create intriguing opportunities for discovery through comparative tasting.

Two “Post-Fermentation Soak” Experiments from Gaharo Hill

The first two coffees, representing the 2020 Long Miles Harvest and kept pristine in the freezer since their arrival, were processed from the same small allotment of cherry that was delivered to Bukeye washing station on June 9, 2020. The default approach to wet processing at Bukeye includes an 8-10 hour soak of the coffee in clean water (after fermentation/washing and before the parchment is transferred to raised beds to be dried). We have heard a variety of theories regarding the impact of the soak on eventual cup quality. Some have suggested that this step results in “cleaner” coffee (both physically, and in the cup), and we have heard anecdotal opinions that the soak also results in “brighter” cup profiles, juicier acidity, etc. For our team, a big motivation for this experiment was our desire to put some of these ideas to the test on a blind cupping table! Having committed to buying the small lot from Gaharo Hill, we asked the Long Miles team if they could process half of it with the traditional soak and half without. Thanks to their amazing support, we now have the opportunity to assess the impact of this processing variable through comparative tasting.

Four “Reduced Oxygen” Experiments from Mutana Hill

Over the past decade, there has been growing interest within the specialty coffee industry in experimental processing approaches that seek to manipulate the “fermentation stage” in various ways. Whether employed to pursue a desirable standard of control and repeatability in coffee processing, or to develop interesting new flavor profiles in the cup, these techniques have been increasingly trendy in recent years, and words such as “anaerobic”, “aerobic”, and “carbonic maceration” have become marketing buzzwords on producer, importer, and roaster coffee descriptions around the world. Among these terms, “anaerobic” is perhaps the most commonly used - often as a description of coffee fermentation that occurs in a sealed container or other low oxygen environment.

At Passenger, it continues to be the case that the majority of the coffees that we are most excited to drink, most inspired to roast, and most proud to share are examples of traditional processing approaches (mostly washed, sometimes honeys, sometimes naturals). This is simply and purely a reflection of our team’s subjective taste preferences and absolutely not a judgment of what anyone else enjoys or is motivated to produce. But while we may have slightly conservative tastes in today’s coffee market, we are also committed to learning, and fascinated by experimentation - especially in collaboration with producers with whom we have cultivated trust through long term partnership.

Near the start of 2021, as a part of Burundi harvest planning discussions with the Long Miles Team, we learned more about the “reduced oxygen process” that the team at Heza washing station was developing. We were interested to pursue a comparative tasting experiment to explore this processing approach, and asked the team at Long Miles if it would be possible to forward-book four bags of coffee from Mutana hill for this purpose. At the time of writing, we are proud to share the results of this 2021 experiment: four distinct microlots from the same cherry delivery that were fermented for different durations in sealed Afri-tank containers (creating a reduced oxygen environment).

The reduced oxygen process employed by the Long Miles team is a simple variation of traditional wet processing in Burundi. Freshly harvested coffee cherry is delivered to the washing station where it is sorted for ripeness and weighed for farmer payment. The coffee is then de-pulped - at which point the experimental phase begins: rather than undergoing a fermentation stage in an open air tank, the mucilage-coated parchment is placed in a sealed Afri-tank container. The four microlots that Passenger contracted for this experiment were kept sealed in the Afri-tank containers for four different time periods: 36hrs, 48hrs, 60hrs, and 72hrs. When the target fermentation time was reached, the parchment was removed from the tanks, washed in grading channels with fresh water, and then dried on raised beds.

We find each of these experimental lots to be thoroughly enjoyable when brewed individually, and it is quite a fascinating experience to taste them as a group. For those that would like to enjoy the experience of tasting the four coffees comparatively, we will be offering a special Mutana Tasting Box, including a 5oz bag of all four lots, while supplies last.

Exploring Processing with the Long Miles Coffee Project