Unraveling the 'Winey' and 'Funky' Notes in Your Coffee: A Processing Deep Dive

Question: If I’m curious about the origin of a “winey” or “funky” note in my coffee, what processing method should I investigate further?

The world of specialty coffee is a realm of intricate flavors, where terms like ‘winey’ and ‘funky’ can evoke a spectrum of sensory experiences. For the discerning coffee enthusiast, understanding the origins of these unique taste sensations is an exciting journey. If you’ve encountered these notes in your brew and are eager to pinpoint their source, the spotlight should turn towards specific coffee processing methods, particularly those involving controlled biological transformations.

The Role of Fermentation in Flavor Development

Fermentation is a critical stage in coffee processing, where microorganisms interact with the coffee cherries, breaking down mucilage and sugars. This biological activity directly influences the chemical compounds that eventually contribute to the aroma and taste of the roasted bean. Research indicates that different fermentation protocols can significantly impact the resulting coffee quality and consumer satisfaction [3]. Specifically, studies have highlighted that both aerobic and anaerobic fermentation treatments have a positive influence on key factors like pH, acidity, and the concentration of volatile compounds [3]. This is in contrast to treatments involving high concentrations of CO₂, which have shown an inhibitory effect on these desirable flavor precursors.

Exploring Aerobic and Anaerobic Pathways

When investigating ‘winey’ or ‘funky’ notes, the distinction between aerobic and anaerobic fermentation processes becomes particularly relevant. Aerobic fermentation occurs in the presence of oxygen, while anaerobic fermentation takes place without it. The specific conditions, including the duration of fermentation and the absence or presence of oxygen, can lead to the development of distinct flavor profiles. For instance, some studies on coffee pulp wines, which undergo fermentation, report the presence of a ‘brandy flavor’ and other complex notes like honey, spice, fruit, and smoke, attributed to specific volatile compounds such as phenylethyl alcohol and ethyl esters [5]. While these studies focus on pulp wines, the underlying principle of microbial action during fermentation influencing complex flavor notes is directly applicable to coffee bean processing.

Beyond Fermentation: Other Processing Considerations

While fermentation is a prime suspect for ‘winey’ or ‘funky’ characteristics, it’s worth noting that other processing stages can also contribute to a coffee’s flavor complexity. For example, the drying phase, which follows fermentation and washing, plays a role in preserving the bean’s inherent qualities. The water activity of different coffee co-products, such as silverskin and cascara, can vary significantly based on their processing and drying, influencing their stability and, by extension, their contribution to the final cup [4]. Furthermore, the cultivation environment, including growing altitude, has been shown to influence flavor precursors and sensory characteristics [6]. However, for the specific profile of ‘winey’ or ‘funky’ notes, the controlled biochemical transformations occurring during fermentation are most likely to be the primary drivers.

Understanding the ‘winey’ or ‘funky’ notes in your coffee is an invitation to explore the fascinating science behind its creation. The evidence strongly suggests that the type of fermentation employed—particularly aerobic and anaerobic methods—is a crucial area for further investigation. These processes unlock a complex array of volatile compounds that define these distinctive and often sought-after flavor characteristics in the world of coffee.

References

[1] — Ernesto Illy, Luciano Navarini — Neglected Food Bubbles: The Espresso Coffee Foam. — 2011-Sep — https://pubmed.ncbi.nlm.nih.gov/21892345/ [2] — Magdalena Zdanowicz, Marta Rokosa, Magdalena Pieczykolan, Adrian Krzysztof Antosik, Katarzyna Skórczewska — Biocomposites Based on Wheat Flour with Urea-Based Eutectic Plasticizer and Spent Coffee Grounds: Preparation, Physicochemical Characterization, and Study of Their Influence on Plant Growth. — 2024-Mar-06 — https://pubmed.ncbi.nlm.nih.gov/38473683/ [3] — Gustavo Galarza, Jorge G Figueroa — Volatile Compound Characterization of Coffee ( — 2022-Mar-21 — https://pubmed.ncbi.nlm.nih.gov/35335365/ [4] — Katarína Poláková, Alica Bobková, Alžbeta Demianová, Marek Bobko, Judita Lidiková, Lukáš Jurčaga, Ľubomír Belej, Andrea Mesárošová, Melina Korčok, Tomáš Tóth — Quality Attributes and Sensory Acceptance of Different Botanical Coffee Co-Products. — 2023-Jul-11 — https://pubmed.ncbi.nlm.nih.gov/37509767/ [5] — Rongsuo Hu, Fei Xu, Liyan Zhao, Wenjiang Dong, Xingyuan Xiao, Xiao Chen — Comparative Evaluation of Flavor and Sensory Quality of Coffee Pulp Wines. — 2024-Jun-27 — https://pubmed.ncbi.nlm.nih.gov/38999011/ [6] — Rongsuo Hu, Fei Xu, Xiao Chen, Qinrui Kuang, Xingyuan Xiao, Wenjiang Dong — The Growing Altitude Influences the Flavor Precursors, Sensory Characteristics and Cupping Quality of the Pu’er Coffee Bean. — 2024-Nov-28 — https://pubmed.ncbi.nlm.nih.gov/39682914/ [7] — Nerea Núñez, Clara Martínez, Javier Saurina, Oscar Núñez — High-performance liquid chromatography with fluorescence detection fingerprints as chemical descriptors to authenticate the origin, variety and roasting degree of coffee by multivariate chemometric methods. — 2021-Jan-15 — https://pubmed.ncbi.nlm.nih.gov/32608518/ [8] — Magdalena Słowik-Borowiec, Bernadetta Oklejewicz, Maciej Wnuk — A Cascara-Infused Caffeine Drink as a Social Beverage. — 2025-Jun-26 — https://pubmed.ncbi.nlm.nih.gov/40649267/