Christopher Feran

The Foundations of Post-Harvest Processing To understand the modern coffee market, we must first dismantle the oversimplified labels of Washed and Natural. Christopher Feran, a consultant and owner of Aviary, suggests a more intuitive taxonomy based on a single decision: what happens to the coffee cherry? Traditionally, the industry viewed this as a binary choice between dry processing (keeping the seed inside the fruit) and wet processing (pulping the seed out). However, the landscape has shifted. Modern processing now includes a critical pre-drying phase. Producers are increasingly manipulating the cherry before it ever hits a drying bed. This includes aerobic or oxidized environments where cherries sit in open trays, allowing enzymatic activity to darken the fruit and break down cellular structures. Conversely, sealing those cherries in tanks with airlocks creates an anaerobic environment. This distinction is no longer just a footnote; it is the primary driver of the intense, fruit-forward profiles dominating specialty coffee shop shelves. The Myth of the Uniform Process Regional traditions often cloud our understanding of what a label like "washed" actually means. In Kenya, a washed coffee typically undergoes a rigorous double fermentation, sometimes involving holding pens where coffee is dried to 20% moisture, rested, and then dried again. This is worlds apart from the traditional Ethiopian washed method, which often utilizes large concrete tanks for submerged fermentation. Even the popular Honey Process is frequently misunderstood. While marketed as "Yellow," "Red," or "Black" honey based on the amount of mucilage left on the seed, these distinctions are often imprecise. Producers adjust the aperture of disc pulpers to leave behind varying degrees of fruit flesh, but because coffee cherries vary in size, the result is never perfectly uniform. Feran notes that many producers start with black honey simply because they haven't yet mastered the fine mechanical adjustments needed for lighter honey styles. It’s a process defined by mechanical friction and guesswork as much as by chemistry. Precision Fermentation and Microbial Control The most significant leap in recent years involves temperature control and microbial modulation. Producers have realized they can act as laboratory technicians, favoring specific populations of microbes to achieve desired flavor outcomes. Fermentation is, at its core, controlled rot. By modulating temperature, a producer can encourage Lactic Acid Bacteria, which produces a creamy acidity and brightness, or favor acetic acid families. Carbonic Maceration, a term borrowed from the Beaujolais wine region, takes this a step further. By flushing fermentation tanks with carbon dioxide, producers expel oxygen and select for specific microbes while eliminating most yeasts and acetic acid bacteria. This level of control allows for a level of consistency that was historically impossible in wild, open-air fermentations. It transforms the processing station from a utility shed into a biocultural lab. The Rise of Co-fermentation and Infusion We are currently witnessing a polarizing trend: the addition of external ingredients during processing. Yeast Manipulation is the most widely accepted form, where commercial wine yeasts are added to out-compete native microbes and amplify specific esters (aromatic compounds). More controversial is Co-fermentation, where fruits like pineapple or melon are added to the fermentation tank. This isn't just about adding flavor; the fruit introduces new sugars and acids that change how the coffee ferments. Then there is Infusion. This involves adding food-grade flavor oils or aromatics like lemongrass or bergamot peel, often during the drying phase. While some purists view this as "cheating" or a way to mask low-quality beans, Feran argues for a different perspective. By performing these infusions at the source, the value remains with the producer rather than a commercial flavorist in a secondary market. It is a pragmatic response to a consumer base that increasingly demands high-impact, "aha" flavor moments. Market Realities and the Producer’s Risk Despite the excitement surrounding these experimental lots, they represent a massive risk for the average smallholder. Most producers in the value stream cannot afford to jeopardize their entire harvest on a experimental anaerobic batch that might develop a "boozy funk" or phenolic defect if improperly managed. The pressure from specialty buyers for constant innovation puts a strain on those who lack the technical education or infrastructure to measure pH, temperature, and moisture with precision. Furthermore, the industry faces a transparency crisis. When a roaster reneges on a contract because a shipment doesn't perfectly match a pre-shipment sample, the producer is left with a niche product that may not sell on the local market. Projects like Aviary attempt to bridge this gap by committing to purchases regardless of minor profile shifts, recognizing that processing is a living, variable art. Conclusion: The Future of Sensation Processing is no longer just a way to prepare coffee for export; it is an active tool for flavor design. As we move forward, the line between "pure" coffee and "designed" beverages will continue to blur. Whether through proximity-based scenting on drying patios or high-tech CO2 injection, the goal remains the same: increasing the value of the crop. The challenge for the industry will be maintaining food safety and transparency while satisfying a market that has developed a seemingly bottomless appetite for novelty. Understanding these processes isn't just for experts; it's the only way for consumers to make informed choices in an increasingly complex cup.