Processing Methods

Processing methods are the soul of coffee’s transformation—a stage where the seeds of possibility bloom into the vibrant flavors we love to share. Few steps in coffee’s journey have as much impact on taste, and the endless debates and philosophies around “proper” processing speak to its importance. Naturally, we have strong opinions, and more importantly, you can taste them in every cup.

 

The purist’s lens views processing as a window to terroir, the story of a coffee’s birthplace written in soil, sunlight, and care. This perspective celebrates transparency, revealing how a cultivar is shaped by its environment, enriched by the minerals and nutrients of its home. Here, human hands act as caretakers, preserving the coffee’s integrity rather than imposing on it. Flowing naturally from this philosophy, we encounter the wet (or washed) process. It’s a method that sings of clarity and brightness, uncovering the pure, unadulterated essence of the coffee’s origin.

 

 

But coffee is also a canvas for experimentation, where bold creativity dances with nature’s unpredictable rhythms. As with the dry (or natural) process, which was once dismissed by purists for its susceptibility to over-fermentation yet later embraced as a cornerstone of tradition, experimental processing methods are reshaping perceptions today. Advances in technology and shared global knowledge have unlocked new realms of possibility, turning coffee into a playground for flavors that can be electric, fruit-forward, spiced, or even otherworldly. With extended fermentations and innovative approaches capturing the imagination of producers, coffee has become akin to milk transforming into cheese or a Belgian ale taking on its signature funk. Microorganisms and fermentation weave their magic, creating flavors as complex and layered as the stories behind them. The curiosity and open-mindedness driving this shift signal an exciting era for coffee, where the boundaries of taste are as limitless as the creativity of those who craft it.

 

 

At Chromatic Coffee, we embrace the full spectrum of processing methods to express what we love and who we are. We celebrate tradition and push boundaries, marrying the agricultural roots of the Valley of Heart’s Delight with the innovation of Silicon Valley. Coffee drinking is evolving, and we’re not just keeping pace—we’re helping to write its next chapter. With this commitment to innovation and heritage in mind, let’s explore the anatomy of the coffee cherry to better understand its journey.

 

A Closer Look at the "Coffee Cherry"

 

To truly appreciate coffee processing, it helps to peek inside the fruit—the coffee cherry, or berry—and discover the layers that influence its journey from shrub to mug. Here’s an anatomy lesson, coffee-style:

 

 

From the inside out:

 

Coffee Seed (Endosperm): The heart of it all—the part we roast, grind, and brew. It's the soul of every coffee experience, holding within it a symphony of flavors just waiting to be unlocked.

 

Silver Skin (Spermoderm): A delicate sheath that clings to the seed and becomes the flaky chaff we see during roasting—a whisper of the cherry’s former life.

 

Parchment (Endocarp): The coffee seed's armor, a papery layer that protects it during drying and storage, removed later during milling to reveal the treasure within.

 

Palisade Cells (Parenchyma): The sticky, sugar-rich mucilaginous layer becomes a playground for fermentation, where natural alchemy begins to unravel the cherry’s hidden potential, turning sweetness into symphonies of flavor. Its role in breaking down and transforming sugars is critical to developing complex flavors.

 

Mucilage/Pulp (Mesocarp): The sticky-sweet layer that surrounds the seed, rich with fruity notes and possibilities. In certain processes, this pulp is left on the seed, adding depth and character to the final cup.

 

Outer Skin (Epicarp): The vibrant, colorful outer shell that shields the cherry from the elements. It’s often stripped away early in processing, but its presence during natural processes can introduce bold, fruity undertones.

 

This is the coffee cherry: a layered masterpiece, where every component plays a role in shaping the journey from seed to sip.

 

 

The Traditional Methods

 

When it comes to processing coffee, traditional methods offer a foundation steeped in heritage, practicality, and time-tested techniques. Each approach interacts with the coffee cherry in a unique way, unlocking distinct flavors that tell the story of both the land and the process itself.

 

Dry Process (Natural)


Often called the most straightforward method conceptually, the dry process (or natural process) can also be one of the most challenging to execute with consistency. Once the cherries are plucked at their ripest, they are laid out under the sun’s embrace, where each one slowly transforms into a radiant gem, imbued with the vibrant energy of its environment. This can happen on expansive concrete patios, rooftops in Yemen, or the iconic raised beds of Ethiopia. Alternatively, some opt for mechanical drying in large rotating ovens. While efficient and space-saving, mechanical drying can sometimes sacrifice cup quality, which is why we rarely choose this option for our offerings.

The beauty of the dry process lies in its ability to highlight bold, fruit-forward profiles with viscous body, and flavors as vibrant as the landscapes where these coffees are born. However, precision is key; improper drying can lead to unwanted fermentation or off-flavors, making this traditional method both art and science.

 

Wet Process (Washed)


Also known as the "washed" method, wet processing emphasizes clarity and purity in the cup, stripping the fruit from the seed to reveal its innate characteristics. We prefer the term "wet" over "washed," as the latter might imply other methods are somehow less clean, which couldn’t be further from the truth.

This process begins with rinsing harvested cherries to remove dirt and debris. As the outer skin is gently stripped away by the depulper, (despite its confusing name, also called a pulper) the hidden seed begins to reveal itself, while the fruit's flesh sometimes finds a second life as cascara, a delicate infusion of its past sweetness. The coffee, still covered in its sticky mucilage, is left to ferment in tiled tanks for 12–72 hours, depending on factors like temperature and humidity. This fermentation stage breaks down the mucilage, allowing it to be washed away with water as the coffee moves through channels. What remains is the parchment layer, ready for drying.

Drying can take place on patios, raised beds, or (for some producers) in mechanical dryers, though we avoid the latter as we believe they compromise cup quality. Wet processing delivers crisp, clean flavors, offering a window into the true essence of the coffee’s terroir.

 

Honey Process (Pulped Natural)

 

Nestled between the dry and wet methods lies the honey process, a technique named not for its taste but for the sticky, honey-like texture of the mucilage that clings to the beans during drying. In Brazil, it’s often referred to as "pulped natural," though we steer clear of the term “semi-washed” due to its association with wet hulling—an entirely different process yielding distinct flavors.

Honey processing begins much like the wet process: ripe cherries are rinsed clean and depulped, their vibrant skins removed. But here’s where the magic diverges—rather than washing the mucilage away, it’s intentionally left on the beans as they dry. This layer, rich with sugars and nutrients, transforms as it oxidizes, giving rise to a dazzling spectrum of flavors and profiles:

 

White Honey: Barely a whisper of mucilage remains, crafting a cup as clean and delicate as a morning dew.
Yellow Honey: A bit more mucilage lends balanced notes of subtle sweetness and soft acidity.
Red Honey: With a generous layer of mucilage, the profile deepens, bursting with bold, fruity character.
Purple Honey: Prolonged oxidation uncovers layers of complexity, unveiling flavors as intricate as a well-aged wine.
Black Honey: The pinnacle of intensity—maximum mucilage and extended drying time culminate in a cup that’s rich, spiced, and profoundly wine-like.


The honey process doesn’t just sit at the crossroads of tradition and innovation; it invites bold experimentation. In modern methods, producers weave honey-like stages into groundbreaking processes such as double anaerobic fermentations, blending time-honored techniques with cutting-edge creativity. It’s a testament to coffee’s limitless potential—a harmony of natural beauty and human ingenuity.

 

Each of these traditional methods is a testament to the craftsmanship and care behind every coffee. They are the foundation from which we continue to build, explore, and redefine what coffee can be.

Other Classic Methods of note:

 

  • Wet Hulling (Giling Basah): Common in Indonesia, this method removes parchment while the bean is still wet, creating earthy, full-bodied profiles.
  • Double Washed (Kenya Style): Features an extra fermentation and rinse stage for exceptionally clean, vibrant coffees.

 

Innovation in Coffee Processing: A Flavor Revolution

If you thought coffee processing was just about drying beans on a patio, buckle up. These new methods are redefining what coffee can taste like. Producers are turning to science and creativity to push boundaries, crafting coffees that blow our minds (and palates). Think of it like a new wave of craft brewing or wine-making, where every step has a purpose and every experiment tells a story.

 

Mossto:  Reclaimed Processing

A natural fermentation method that uses the juice from previously fermented cherries to enrich the next batch. Known as film yeast fermentation, it creates coffees that are deeply complex and flavorful.

 

Double Anaerobic Fermentation: Two Times the Magic

This one's for the fermentation nerds. In Double Anaerobic Fermentation, coffee cherries start by fermenting in an oxygen-free tank. This stage enhances fruity, lactic notes (think yogurt meets tropical fruit). Then, the cherries are pulped, and the mucilage-covered beans go back into another anaerobic environment for a second round. Each stage is carefully timed and monitored to avoid sour flavors while amplifying sweetness and complexity. The result? A cup that’s bold, layered, and smooth—like a well-told story.

 

Thermal Shock: Science Meets Drama

Ever tried flash-freezing your coffee? Okay, maybe not, but Thermal Shock isn’t far off. It’s all about alternating between hot and cold water during fermentation. Why? The sudden temperature changes stress the coffee at a cellular level, releasing sugars and aromatics you didn’t even know were there. It’s like hitting "shuffle" on your coffee’s flavor playlist: bright, sweet, and unexpectedly smooth.

 

Thermal Stroke: Coffee's Slow Burn

Thermal Stroke takes the temperature game further by extending it over the drying phase. Think hot and cold cycling, but drawn out over days or even weeks. This extended exposure allows deeper caramelization of sugars and more nuanced flavor development. The result? A coffee with drama, elegance, and the kind of complexity that keeps you coming back for another sip.

 

Co-Fermentation: Coffee’s Wild Side

What happens when coffee parties with passionfruit, cinnamon, or even pineapple? Co-Fermentation, that’s what. Producers add fruits, spices, or herbs to the mix during fermentation, allowing the coffee to absorb their flavors. The science? These additives bring in their own unique microbial ecosystems, creating a sensory crossover event. Think tropical vibes, floral explosions, or even warm, spicy undertones. It’s coffee reinvented, one experiment at a time.

 

Koji Processing: Sake, Meet Coffee

This one’s for the culinary crossover fans. Koji Processing borrows its magic from sake brewing. Koji mold (yep, mold) breaks down coffee mucilage with enzymes, unlocking natural sugars and creating savory-sweet umami notes. The result? Coffees that feel like they’ve been aged in the finest barrels, full of intrigue and surprising sweetness.

 

Hybrid Processes: The Best of Everything

Coffee processing is no longer about sticking to one script. Hybrids mix methods to create something entirely new:

  • Supernatural: Start with anaerobic fermentation, then dry the cherries like a natural process. The result? Bold fruity notes with a cleaner finish.
  • Hydro-Honey: A honey process with extra rinsing stages. It balances the clarity of a washed coffee with the sweetness of honey.
  • Controlled Carbonic Maceration: A mic-drop hybrid that uses precise pH and CO2 controls to finesse every flavor note.

 

Why These Methods Matter

These innovative methods represent the coffee industry's shift towards a more scientific, precise approach, expanding the boundaries of what coffee can be. Each technique requires a mix of experimentation and understanding of biochemistry, making them accessible primarily to producers with the resources and willingness to take risks.

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