Unveiling the Science behind the Enchanting Aroma of Fermented Coffee

Photo of author

As an Amazon Associate, I earn from qualifying purchases. This post may contain affiliate links, meaning I may receive a commission if you purchase using these links.

Fermented coffee is a unique and intriguing take on regular coffee that has been gaining in popularity in recent years.

This aroma has puzzled scientists for decades, but recently, a team of researchers has unlocked the secrets behind the fruity aroma of fermented coffee.

Fermented Coffee
Coffee cherries

What is Fermented Coffee?

To produce fermented coffee, coffee beans are left to soak in the natural juices found in the coffee cherries, unlike the usual coffee processing method that involves washing and drying the cherries.

Fermented coffee has a fruity taste, similar to raspberries, with a hint of rose, instead of the usual bitter taste.

During fermentation, yeast and bacteria on the cherry’s skin eat the sugars and amino acids in the cherry, which changes the flavor of the coffee.

Where can I buy It?

Amazon offers a wide range of options for purchasing fermented coffee, with one of the most popular options being DAYES Fermented Whole Bean Coffee.

Days Fermented Coffee Beans
DAYES fermented coffee, aka enzyme coffee

You can find different types of fermented coffee with varying taste profiles, aromas, and origins.

Some options may come from small-scale farmers or specialty coffee roasters, while others may be from popular coffee brands.

The Science of Fermented Coffee’s Flavor & Aroma

The fruity aroma of fermented coffee is caused by the presence of volatile organic compounds (VOCs) that are produced during the fermentation process1.

These VOCs are responsible for fermented coffee’s unique and delightful aroma.

“The volatile organic compounds belonging to different chemical classes identified in roasted coffee, such as alcohols, aldehydes, esters, furans, ketones, phenols, pyrazines, pyridines, pyrroles, and sulfur compounds, define the sensory properties of coffee.

Some chemicals, such as furans, may harm human health. Volatile organic compounds with low odor thresholds make significant olfactory contributions to coffee flavor.”

Professor Thomas Dippong, Facutly of Science, Romania

Translation: Fermented coffee tastes and smells unique because of its chemicals. But some of those chemicals, like furans, can harm you. Strong-smelling chemicals can affect the flavor and scent of fermented coffee.

During the fermentation process, microorganisms break down the sugars in the coffee beans and produce a variety of VOCs, including alcohols, ketones, and esters.

These compounds are responsible for fermented coffee’s fruity, floral, and wine-like aromas.

Roasted And Fermented Coffee Beans
Roasted fermented coffee beans

The Fermentation Process

The fermentation process is a crucial step in the production of fermented coffee. The process involves soaking the coffee beans in water for 12 to 24 hours.

During this time, naturally occurring microorganisms on the coffee beans consume the sugars and produce the VOCs that give fermented coffee its unique aroma.

After fermentation, the coffee beans are washed, dried, and then roasted to produce the final product.

Coffee Fermentation Process
The coffee bean fermentation process

The Impact of Fermentation on Coffee Flavor

The fermentation process not only produces the fruity aroma of fermented coffee but also significantly impacts the coffee’s overall flavor.

Fermented coffee has a unique and complex flavor profile that differs from traditional coffee.

Fermented Coffee
Fermented coffee has a rose-like aroma.

Various factors, including the type of coffee bean, the fermentation time, and the microorganisms present during the fermentation process, influence the flavor of fermented coffee.

Depending on the specific fermentation conditions, the resulting flavor can range from fruity and floral to earthy and spicy.


In conclusion, the aroma of fermented coffee is a complex and fascinating subject that has recently been studied in-depth by a team of researchers at the Coffee Excellence Center in Zurich.

The discovery of the science behind the fruity aroma of fermented coffee is an exciting development for coffee enthusiasts worldwide.

Understanding the fermentation process and its impact on the flavor and aroma of coffee can help coffee producers create unique and delicious coffee products that stand out in the market.


  1. Dippong, T.; Dan, M.; Kovacs, M.H.; Kovacs, E.D.; Levei, E.A.; Cadar, O. Analysis of Volatile Compounds, Composition, and Thermal Behavior of Coffee Beans According to Variety and Roasting Intensity. Foods 2022, 11, 3146. https://doi.org/10.3390/foods11193146
Avatar Of Kelsey Todd
With over two decades in the coffee industry, Kelsey is a seasoned professional barista with roots in Seattle and Santa Barbara. Accredited by The Coffee Association of America and a member of The Baristas Guild, he combines practical expertise with a profound understanding of coffee's history and cultural significance. Kelsey tries his best to balance family time with blogging time and fails miserably.

Leave a Comment