What is Experimental Coffee Processing?

Some coffees highlight clarity, sweetness, and origin in a familiar way. Others show what coffee can become when a producer starts asking a different question.

Not just, “How do we bring out what’s already in this bean?” but, “How precisely can we shape the process?”

That is the space experimental processing lives in.

Extended fermentation, co-fermentation, carbonic maceration, thermal shock, advanced processing, different names, same broad territory. These methods emerged when producers began treating fermentation as something they could measure, guide, and intentionally shape.

Experimental processing goes beyond traditional washed, natural, or standard anaerobic methods. The goal is to shape the fermentation environment and, by extension, what shows up in the cup.

What these methods share is intention: a producer making deliberate decisions at every stage of processing to bring something distinct and expressive to the cup.

Where It Started

The 2010s were a turning point.

A new generation of producers, many approaching coffee through agriculture, chemistry, microbiology, and winemaking, began treating fermentation less like a background step and more like a tool. Sealed tanks, controlled temperature, measured pH, sugar content, fermentation time, these became variables that could be managed with precision.

When Sasa Sestic won the 2015 World Barista Championship using a coffee processed with carbonic maceration, a winemaking technique adapted for coffee, it brought that shift into global view. In coffee, carbonic maceration usually means whole cherries are placed in a sealed, carbon dioxide-rich environment, where fermentation begins inside the intact fruit.

Luis Eduardo Campos, working at Cordillera de Fuego in Costa Rica’s Tarrazú region, became known for controlled fermentation and thermal shock processing, showing how carefully managed fermentation could create coffees with depth, sweetness, and a distinctly layered cup.

Common Methods

Extended fermentation is one of the simplest ways to shift a coffee’s profile. Traditional fermentation often runs within a relatively short window, depending on method, climate, and producer. Extended fermentation lets the process continue longer, sometimes 48, 72 hours, or more.

The risks are real. Fermentation can go too far, and when it does, the coffee may turn harsh, sour, vinegary, or muddled. But when a producer knows their environment well enough to manage the process, extended fermentation can create more developed acidity, deeper sweetness, and a more layered cup.

Co-fermentation takes the controlled environment one step further by introducing external ingredients into the fermentation tank alongside the coffee. Whole fruit is common, passion fruit, cacao pulp, lemon zest, banana, and grape must. Some producers work with specific yeast strains, botanicals, or spices.

This is worth distinguishing from flavored coffee. Flavored coffee is usually treated after roasting, with flavoring compounds or oils added on top of the finished bean. Co-fermentation happens at the green stage, during processing, through living biological processes. The compounds that influence the cup become part of the coffee’s development, not a coating added later.

Who’s Pushing the Category?

Colombia is one of the clearest places to look if you want to understand experimental processing at its most developed.

Diego Samuel Bermudez of Finca El Paraíso and Wilton Benitez of Granja Paraíso 92 are two producers widely associated with advanced fermentation, thermal shock processing, and highly controlled cup profiles. Their lots are sought out by roasters around the world and have helped define what this category can taste like at the highest level.

Experimental processing is not random. At its best, it is deeply intentional.

What It Tastes Like

Experimental lots often sit at the "funky" end of the spectrum. That is not a criticism, just a direction.

Extended fermentation can bring dense sweetness, deeper fruit, heavier body, and a more lingering cup. Co-ferments can be vivid and direct, with fruit, floral, spice, or tropical notes that feel unusually specific. Carbonic maceration can bring heightened aromatics, clarity, and a fruit-forward cup. Thermal shock coffees can feel especially structured, with intense aromatics and a polished, almost electric clarity when done well.

When it works, the coffee’s own character still comes through underneath. When it does not, the processing can overwhelm everything. The difference is almost always the producer.

What We’re Tasting

We’re often drawn to coffees shaped by thoughtful, producer-led processing, where fermentation, drying, and variety bring something expressive to the cup. Last year, that looked like a thermal shock process from the wonderful Luis Eduardo Campos at Cordillera de Fuego in Costa Rica. We also loved his seasonal anaerobic, which we affectionately called “Cozy in a Cup.”

Right now, Montano Jaguar, our anaerobic honey from Tarrazú, Costa Rica, lives in that same spirit. It is not a co-ferment or thermal shock lot, but it carries the same intentional approach to fermentation, sweetness, and structure. For anyone curious about this side of coffee but not quite ready for the wildest end of the spectrum, this is a beautiful place to start.

Peñas Blancas Java, from our Apex Reserve collection, sits near that edge in a different way. It is a natural process coffee from a processing center in Acevedo, Huila, led by Nestor Lasso and Jhoan Vergara, two producers connected to Colombia’s new wave of innovative coffee processing. It is fruit-driven, vivid, and unmistakably expressive, the kind of coffee that shows how far careful variety selection and processing can take a cup without needing to be labeled a co-ferment.

That is the space we love to explore. When the right lot comes along, whether it is thermal shock, anaerobic, co-fermented, carbonic maceration, or simply unusually expressive, this blog goes up first. Join our email list for updates and more.