What Do All These Coffee Processing Terms Mean?

Confused about all the different coffee process terms you keep seeing on bags or in barista competitions? You are not alone. Coffee processing plays a huge role in shaping the flavor of your brew, sometimes more than the roast itself. From clean and crisp to wildly fruity or syrupy sweet, the method used to prepare coffee after harvesting can radically change your cup.

In this deep dive, we walk through seventeen of the most notable coffee processing methods. This includes classic approaches like washed, natural, and honey, as well as experimental styles like carbonic maceration, frozen cherry, and thermal shock. If you have ever wondered what a “black honey” or “anaerobic” process actually means, or why decaf processes differ, this guide will answer those questions and more.

The Most Common Processing Methods

The three most widely used processing methods globally are washed (wet process), natural (dry process), and honey (semi-washed). These define the starting point of coffee flavor, and are often used to control acidity, clarity, and sweetness. From there, innovative and experimental methods build on these foundations. Below is a breakdown of all major processing techniques in alphabetical order.

Anaerobic Fermentation

This method ferments coffee in airtight tanks without oxygen. It intensifies sweetness and complexity by encouraging unique microbes to flourish. Flavors tend to be bold and fruity, with notes of tropical fruit, red wine, or bubblegum. Anaerobic processes often result in syrupy, jam like mouthfeel.

Anoxic Fermentation

Often confused with anaerobic, anoxic fermentation means “without oxygen” but also removes carbon dioxide. It uses sealed chambers and nitrogen flushing. This ultra controlled method produces balanced and clean profiles, sometimes with exotic floral or spiced notes.

Black Honey

One of the darkest honey process styles, this method leaves almost all of the mucilage (the sticky fruit layer) on the beans during drying. Beans dry slowly under shade, resulting in deep sweetness, low acidity, and complex fruit notes. Black honey coffees are labor intensive but reward drinkers with syrupy, full-bodied cups.

Carbonic Maceration

Borrowed from the wine industry, this involves placing whole cherries in a CO₂ rich environment before fermentation. The coffee ferments from the inside out, producing aromatic complexity and intense fruit forward notes. Often used in competition coffees, it creates unforgettable cups with wild, wine like flavors.

Decaf (Sugarcane / EA)

Sugarcane decaffeination (ethyl acetate) uses a naturally derived solvent from sugarcane to remove caffeine. It retains flavor better than many chemical methods. Expect a pleasant balance with mild acidity and rich, caramel or brown sugar notes. At Frequent Coffee, this is our go-to decaf method in blends like Sidekick.

Decaf (Swiss Water Process)

This chemical-free method uses water and activated charcoal filters to remove caffeine. It is very gentle and maintains the original integrity of the bean. This method is ideal for those who are sensitive to chemical decaffeination. You can taste it in our Jitterfree Delight.

Decaf (Carbon Dioxide Process)

The CO₂ method uses supercritical carbon dioxide to selectively remove caffeine. It is precise and leaves flavor compounds intact. It is less common in the United States but growing in popularity due to its clean taste and technical efficiency.

Decaf (Methyl Chloride Method)

Also called the direct solvent method, this uses a chemical compound to strip caffeine. While effective, this method is controversial. We do not offer or recommend this method due to health and flavor concerns.

Double Fermentation

This involves two separate fermentation steps, often both anaerobic. The coffee may be pulped and soaked first, then dried and fermented again. The result is deeply nuanced flavor and complexity with a layered acidity.

Frozen Cherry Processing

In this experimental method, cherries are frozen immediately after picking. This locks in sugars and slows down fermentation. The result can be a more developed sweetness and intense fruit flavors. It is a relatively rare process still being explored in micro-lots.

Honey Process

In this semi-washed style, the skin is removed but some or most mucilage remains. The drying style (shade or sun) and mucilage amount affect the taste. Yellow honey is lighter, while black honey is richer. Honey processes are known for creamy textures and moderate fruitiness.

Lactic Fermentation

This style encourages lactic acid bacteria in sealed or semi sealed tanks. The result is creamy and velvety with distinct sweetness and often a yogurt like or buttery texture. It is especially popular in Latin America.

Natural (Dry Process)

The oldest and most traditional style, natural coffees are dried whole with the fruit still intact. The long contact with sugars leads to intensely fruity, boozy, or winey flavors. It is commonly used in Ethiopia and Brazil, producing some of the world’s most expressive cups.

Thermal Shock

This high-tech method alternates between hot and cold water exposures to influence fermentation and flavor development. It can be paired with anaerobic or carbonic methods. Expect exotic and nuanced profiles. It is mostly found in experimental lots and competition coffees.

Washed (Wet Process)

This clean, precise method removes all fruit before drying. Beans are pulped, fermented in water, washed, and then dried. This leads to clarity, brightness, and higher acidity. Washed coffees are preferred by many for their crisp and articulate profiles.

Yeast-Inoculated Fermentation

Specific strains of wine or beer yeast are added during the fermentation to control flavor development. The result is consistent, vibrant flavors, and can help bring out tropical, floral, or herbal notes depending on the strain.

Wine Process

This experimental method uses leftover wine must (grape skins, stems, juice) during fermentation. While not common, it produces boozy, fermented flavors with deep complexity. It is still being trialed in select regions.

Final Thoughts

As coffee evolves, processing continues to push boundaries. Whether you love a clean washed cup or seek out exotic anaerobics, knowing how your coffee was prepared gives you valuable insight into flavor, quality, and intention. At Frequent Coffee, we obsess over these methods because we know how much they matter to your daily cup.

Want to explore coffees processed with precision and care? Check out our curated decaf collection or follow us for more deep dives into coffee culture and craft.

Got a favorite processing method or a wild experience with an unusual cup? Share it with us over at @frequent.coffee.