The Mouthfeel Clue: Washed vs. Natural Coffee Processes

Question: When tasting a coffee, what’s a quick way to tell if it might be a washed or natural process based on how it feels in your mouth?

The journey of a coffee bean from cherry to cup is a complex one, with processing methods playing a crucial role in shaping its final flavor and texture. For the discerning coffee enthusiast, understanding these nuances can elevate the tasting experience. While aroma and flavor notes are often the primary focus, the way a coffee feels in the mouth—its mouthfeel—can also provide a valuable clue to its processing history. Two of the most common processing methods, washed and natural, often translate into distinct tactile sensations on the palate.

The Clean Acidity of Washed Coffee

The washed (or wet) process involves pulping the coffee cherry, fermenting it to remove the mucilage layer, and then thoroughly washing the beans [6]. This meticulous removal of the fruit pulp before drying is key. Research suggests that washed coffees are often linked to a livelier and more pleasant tartness [5]. This brighter acidity, often perceived as clean and distinct, is a hallmark that can point towards a washed processing method. The absence of the mucilage during drying minimizes the potential for fruity over-fermentation flavors, allowing the intrinsic characteristics of the bean to shine through with a crispness that can be described as refreshing. The pH values of coffee co-products can vary significantly, with some Coffea arabica samples showing a range of 4.22-4.73, indicative of a certain acidity profile that can be characteristic of washed beans [2].

The Velvety Embrace of Natural Processed Coffee

In contrast, the natural (or dry) process involves drying the coffee cherry whole, with the fruit intact around the bean. This method allows the bean to absorb sugars and other compounds from the drying fruit pulp over an extended period. While the exact fermentation times and temperatures can vary widely and influence outcomes, the retention of the fruit layer during drying can impart a distinct character. This often translates to a coffee that feels smoother and more viscous in the mouth, with a perceived fuller body. Instead of a sharp tartness, natural processed coffees can offer a more rounded, sometimes syrupy texture. This difference in mouthfeel is a direct result of the sugars and compounds from the fruit pulp interacting with the bean during the drying phase. While specific studies directly linking mouthfeel to natural processing parameters like fermentation time or pH in this context are limited within the provided data, the sensory outcomes are consistently described as fruitier and often smoother compared to their washed counterparts [3, 4].

Perceiving the Difference

When tasting, pay attention to that initial impression as the coffee coats your tongue. Does it feel sharp, bright, and almost effervescent with acidity? This might be your cue for a washed coffee. On the other hand, if the coffee feels silkier, more substantial, and the sweetness seems more integrated with a lower perceived acidity, you might be experiencing the characteristics of a natural processed bean. This tactile exploration, combined with the aromatic and flavor profiles, offers a more holistic understanding of how processing shapes the final cup. It’s a quick, intuitive way to begin dissecting the complex journey from cherry to your sensory experience.

In essence, the tactile sensation of coffee—whether it’s a bright, clean tartness or a smooth, viscous feel—offers a tangible hint about its origin and processing. By attuning your palate to these subtle differences, you can gain a deeper appreciation for the artistry involved in bringing each unique cup to life.

References

[1] — 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/ [2] — 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/ [3] — 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/ [4] — 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/ [5] — Magdalena Zarebska, Natalia Stanek, Krzysztof Barabosz, Anna Jaszkiewicz, Renata Kulesza, Rafał Matejuk, Dariusz Andrzejewski, Łukasz Biłos, Artur Porada — Comparison of chemical compounds and their influence on the taste of coffee depending on green beans storage conditions. — 2022-Feb-17 — https://pubmed.ncbi.nlm.nih.gov/35177718/ [6] — Ana Paula Pereira Bressani, Nádia Nara Batista, Débora Mara de Jesus Cassimiro, Simone da Fonseca Pires, Hélida Monteiro de Andrade, Disney Ribeiro Dias, Rosane Freitas Schwan — Exploring coffee processing stages: Wet fermentation with and without Saccharomyces cerevisiae vs. Conventional process. — 2025-Jun-25 — https://pubmed.ncbi.nlm.nih.gov/40555793/ [7] — Hao Lin, Edisson Tello, Christopher T Simons, Devin G Peterson — Identification of Non-Volatile Compounds Generated during Storage That Impact Flavor Stability of Ready-to-Drink Coffee. — 2022-Mar-25 — https://pubmed.ncbi.nlm.nih.gov/35408521/