The influence of fermentation on the taste of coffee

When we talk about fermentation, we often think of wine or cheese. However, coffee also undergoes a fermentation process after harvest, and this process strongly influences its aromas. More and more producers are experimenting with controlled fermentation to create unique flavor profiles. Here's how fermentation transforms your cup.

What is coffee fermentation?

Fermentation is a natural process in which the sugars and organic compounds in the coffee cherry are broken down by microorganisms such as yeast and bacteria. It occurs when the sugary pulp surrounding the bean remains in contact with it after harvest. Depending on the duration, conditions, and fermentation methods, the flavor of the coffee can change dramatically.

The main types of fermentation

• Aerobic fermentation: The pulped grains ferment in the open air, sometimes submerged in water. It generally produces greater clarity, marked acidity, and distinct floral or fruity notes.
• Anaerobic fermentation: The beans ferment without oxygen in airtight tanks. This produces coffees with a fuller body, exotic aromas, and increased complexity.
• Experimental fermentations: certain methods inspired by oenology, such as carbonic maceration, allow the development of atypical profiles with aromas of tropical fruits, wine or gentle fermentation.

How does fermentation impact the cup?

• Duration plays an important role. A short fermentation produces fresh, light coffees, while a longer fermentation accentuates sweet, complex, or fermented flavors.
• Temperature is also crucial. Fermentation at a lower temperature preserves fine aromas, while a higher temperature develops heavier flavors.
• The method influences the final result. A natural fermentation process will often produce a fruitier cup than a washed coffee.

Natural versus controlled fermentation

Traditionally, fermentation was used solely to remove the mucilage around the grain. Today, some producers are using fermentation as a creative lever to modulate flavors by controlling parameters such as pH, temperature, and duration.

Which fermented coffees should you choose according to your tastes?

If you like clean, citrusy, and floral coffees, choose traditional fermentations, often using the washed method. If you're looking for more exotic, full-bodied, and complex coffees, opt for coffees that have undergone anaerobic fermentation or carbonic maceration.

Conclusion

Fermentation is a subtle art that profoundly transforms the profile of coffee. When mastered properly, it enriches the aromatic palette and reveals unexpected facets of the terroir. Exploring coffees with different fermentations opens your palate to new flavor dimensions.