Does Anaerobic Fermentation Processing Result in Higher Coffee Body? Exploring Flavor and Mouthfeel

FrontStreet Coffee Introduction: Anaerobic Fermentation Processing Method

The Anaerobic Fermentation Process

Anaerobic fermentation processing — also known as carbon dioxide maceration — is a technique borrowed from winemaking, where grapes are sealed in carbon dioxide gas and pushed into an oxygen-free state. Under those conditions, grapes can convert their own fructose into alcohol even without added yeast, developing special aromas, and the resulting wine shows gentle fragrance and a rich mouthfeel.

The coffee Sasa Sestic himself used at the 2015 WBC came from Colombia's Las Nubes farm — the Rume Sudan variety. According to him, the anaerobic fermentation of those beans mainly involved placing mature coffee cherries in sealed metal containers (stainless steel barrels), injecting carbon dioxide, and expelling the oxygen, so that fermentation and decomposition proceeded in an oxygen-free environment. The method gives the producer real control over pH, gas composition, humidity, temperature, and even the types and quantities of bacteria driving the fermentation, developing better sweetness and more balanced flavors.

That said, the anaerobic methods used by various processing plants today — and by the many sellers touting "anaerobic fermented" green beans — actually differ quite a lot from one another. The technique is still young, so no single standard version exists. Most of what we hear about today traces back to the method Sasa used then, or to modifications of it. Recent experimental offshoots such as anaerobic natural, anaerobic washed, and double anaerobic have appeared one after another, and they are genuinely exciting.

Characteristics of Anaerobic Fermentation Processing

• Stainless steel containers (which don't absorb flavors from previous batches) hold the cherries, allowing for cleaner flavors.
• Fermentation in a sealed environment makes every variable easier to control, so each batch comes out more consistent, and aromatic substances are less likely to volatilize away.
• Oxygen-free fermentation produces rounder flavors, often with cheese and cream aromas.
• Coffee processed this way typically shows fuller body and wine-like aromas.

FrontStreet Coffee Recommendation

Colombia, the birthplace of modern anaerobic experimentation, remains one of the most versatile origins: its coffees serve equally well in espresso blends and pour-over single origins, spanning bright fruit-acid profiles, full-bodied styles, and aromatic, floral lots. FrontStreet Coffee's washed Huila, from the hills of the country's most famous specialty region — planted above 1,500 meters where Colombia's great rivers converge — is medium-dark roasted to bring out black chocolate and nut sweetness, moderate oils, and a full body, working beautifully as pour-over, French press, moka pot, or espresso for americanos and lattes alike.

For a taste of anaerobic processing itself, try the FrontStreet Colombia Frontera Estate Sidra (anaerobic natural). After oxygen-free fermentation, the coffee transforms into richer tropical fruit aromas: medium-light roasted, it delivers complex, heady notes of passion fruit, grape, apricot, and dried fruit whether you brew it as pour-over, cold brew, drip bag, or moka pot.