Why are some coffees more acidic than others?

Coffee acidity is perhaps one of the most misunderstood aspects. For some, it is synonymous with unpleasantness, or even poor quality. For others, it is on the contrary an essential signature of specialty coffees.

So, why are some coffees more acidic than others? And above all, is this acidity really a flaw?

The answer is more nuanced than it seems. Coffee acidity depends on many factors, ranging from the origin of the bean to the extraction method, including roasting. Understanding these elements allows you to better appreciate coffee… and to overcome certain misconceptions.

Coffee acidity: a natural characteristic, not a flaw

Contrary to popular belief, acidity is an integral part of coffee. It is naturally present in the bean, just like sugars, oils, or aromatic compounds.

In a well-crafted coffee, the acidity should not be aggressive. It brings freshness, liveliness, and complexity. We often speak of a “fruity” or “bright” acidity, comparable to that found in certain fruits.

It is this acidity that allows you to distinguish a flat coffee from an expressive one. Without it, the cup lacks definition.

Coffee origin: a determining factor

Terroir plays a major role in coffee acidity.

Coffees grown at high altitudes, particularly in East Africa (Ethiopia, Kenya), generally develop a more pronounced acidity. The climate, soil composition, and slow maturation of the cherries favor the formation of more complex aromatic compounds.

Conversely, coffees coming from regions like Brazil or certain areas of Central America often present a milder acidity, with rounder, more chocolatey profiles. The origin of the coffee therefore directly influences the perception of acidity in the cup.

Coffee variety and processing

Not all coffee varieties produce the same profiles. Some varieties, such as Bourbon or Ethiopian Heirloom, are renowned for their aromatic richness and acidity.

The post-harvest processing method also plays a key role.

A washed coffee often highlights a cleaner and more distinct acidity. Conversely, a natural coffee (dried with the pulp) develops fruitier, sometimes rounder notes, with a less sharp acidity.

These processing choices profoundly influence the final result.

Roasting: revealing or attenuating acidity

Roasting is one of the most important levers. A light or medium roast preserves the coffee's natural acidity and highlights its aromas. This is generally the preferred choice in specialty coffee.

Conversely, a very dark roast tends to mask this acidity. It develops more bitterness and roasted notes, at the expense of aromatic finesse.

This is why some industrial coffees seem less acidic: their roast is often darker, which evens out the taste.

Extraction: an often underestimated factor

Even with a good coffee, a poor extraction can throw the cup out of balance.

Under-extraction can result in an excessive, unpleasant acidity, often perceived as “sour.” Conversely, over-extraction accentuates bitterness and overwhelms the acidity.

The right balance depends on several parameters: grind, water temperature, extraction time, and the method used. For example, a slow extraction (filter, V60) will highlight acidity more than an espresso, which is more concentrated and structured.

Coffee acidity and digestion: beware of confusion

It is important to distinguish two concepts:

• taste acidity (flavor in the mouth)
• gastric acidity (effect on the stomach)

A coffee can be very aromatic and present a beautiful acidity in the mouth, while being well tolerated by the body. Conversely, a coffee that is not very acidic in taste can cause digestive discomfort if it is of poor quality or poorly roasted.

This confusion is at the root of many misconceptions about coffee.

Not all acidic coffees are alike

Coffee acidity can take different forms. It can be bright, like a citrus fruit, milder, like a ripe fruit, or even more floral. In specialty coffee, this diversity is sought after and valued.

An Ethiopian coffee may evoke notes of lemon or red fruits. A Kenyan coffee may present a more intense and structured acidity. These differences contribute to the richness of coffee.

Shoukâ: a balanced approach to acidity

At Shoukâ, acidity is never considered a flaw, but an element of balance to be mastered.

Each coffee is selected for its aromatic profile, then roasted in a way that reveals its qualities without throwing the cup out of balance. The goal is to offer coffees that are clear and accessible, but always expressive.

This approach allows us to offer coffees where acidity is present, but integrated, serving the taste and the tasting experience.

Conclusion: acidity, a key to understanding coffee

Coffee acidity is a natural characteristic, influenced by many factors: origin, variety, processing, roasting, and extraction.

Rather than avoiding it, it is interesting to understand it. A well-mastered acidity brings freshness, complexity, and a true signature to the cup. By learning to recognize the different forms of acidity, it becomes possible to choose your coffee better and appreciate the full richness of specialty coffee.

Sources

• Specialty Coffee Association (SCA)
• Publications on the chemical composition of coffee
• Research on roasting and extraction