How to choose a coffee that is not acidic ?

In the coffee industry, acidity is one of the most complex sensory parameters to master. It profoundly influences the structure of a cup, its vibrancy, balance, and digestibility. Yet, acidity remains a term often misunderstood by the public, despite being fundamental for specialists.

At Café Castelo, our more than thirty years of expertise in artisanal roasting has allowed us to develop a refined and rigorous understanding of coffee acidity. Thanks to a strict selection of 100% Arabica coffees grown at high altitude and to a slow roasting method at low temperature, We are able to offer coffees where acidity is either elegantly highlighted or controlled to create round, smooth and digestible profiles.

This article presents a comprehensive analysis of coffee acidity, integrating the most relevant scientific, agronomic and sensory knowledge, while explaining how our expertise allows us to control its expression.

1. Coffee acidity: a key structural component analyzed by experts

In coffee studies, acidity has nothing in common with gastric acidity or bitterness.
This is a structuring taste parameter, determined by the presence of natural organic compounds such as chlorogenic, citric or malic acids.

These acids play an essential role in:
• aromatic clarity
• the brilliance of the aromas
• the complexity of the sensory profile
• the overall balance of the cup

A coffee without acidity may seem round and sweet, while a coffee where acidity is more present may offer a sought-after liveliness in certain light roasts.

From an expert's point of view, acidity is not a simple sensation:
It is an indicator of quality, freshness and terroir.

2. The determining factors of acidity: a scientific perspective

The acidity of a coffee depends on a set of variables often unknown to the general public, but perfectly controlled by professional roasters.

a) The species and variety of the grain

Café Castelo works exclusively with coffees 100% Premium Arabica, which guarantees a superior aromatic balance.

b) Cultivation altitude

High-altitude coffees ripen slowly, which promotes:
• aromatic complexity
• a finer and better integrated acidity
• a denser grain, therefore more stable during roasting

Our coffees come mainly from terroirs located between 800 and 2,000 meters, an essential criterion for obtaining controlled profiles.

c) The grain processing method

Depending on whether the coffee is washed, natural or honey, the acidity will be different.
A washed coffee, for example, highlights the acidity more.

d) The degree of roasting: the roaster's main tool

This is where Café Castelo's expertise comes into play.

• Light roast : The natural acidity is preserved; the coffee is bright, floral, fruity.
• Medium roast : The acidity decreases, and caramelized notes appear.
• Dark roast : the acids are transformed; the coffee becomes round, sweet, low in acidity.

Whereas industrial roasting uses very high temperatures, sometimes creating a burnt or aggressive acidity, our method slow and at low temperature allows for a natural, progressive and controlled evolution of acids.

Acidity and caffeine are not the same thing.

It is important to clearly distinguish:

• Acidity is the sensation in the mouth and in the stomach.
• Caffeine is the stimulant.

There is generally a little more caffeine in brown coffee than in black coffee, but we are talking about a difference of around 1 to 2%, so it is too small for the majority of people to really feel it in their body.

The intensity of the flavor (stronger, more bitter) is not directly related to the amount of caffeine. A coffee can be very strong, but not necessarily more caffeinated than another.

3. The Café Castelo approach: reducing acidity without compromising quality

Our work aims to provide coffee balanced, digestible and aromatically rich.
Three technical pillars enable us to achieve this result.

1. Strict selection of 100% high-altitude Arabica coffees

This choice guarantees a noble acidity, never aggressive, and a superior aromatic potential.

2. Slow roasting at low temperature

This method:
• Preserves essential oils (cafeol)
• prevents the carbonization of acids
• eliminates unwanted acidic spikes
• ensures a smoother and more stable mouth experience

Few companies still use this type of roasting, as it requires more time, more control and more expertise.

3. Mastery of medium and full-bodied profiles

Medium and full-bodied coffees are naturally milder, as roasting gradually reduces acidic compounds. It is also important to point out that, even when a medium or full-bodied coffee has fruity nuances, these are never expressed in the same way as in a pale coffee: they become darker, more discreet and more integrated into the structure of the coffee, often evoking ripe or candied fruits rather than citrus or bright notes.

The degree of roasting

The degree of roasting is one of the simplest elements for understanding acidity:

• Pale coffees = naturally more acidic (notes of citrus, fruit, floral notes)

• Medium-strength coffees = moderate acidity, rounded

• Strong coffees = very low or non-existent acidity

Therefore, for consumers who want a low-acidity coffee, the most reliable solution is still a medium or dark roast.

4. The role of body pH: why two people do not perceive acidity in the same way

Even when coffee is expertly brewed, the perception of acidity also depends on the Individual pH.
Each person has a different sensitivity depending on:
• food
• the stress level
• the gastric condition
• the consumption of alcohol or tobacco
• medications (including antibiotics)

Thus, a medium-strength coffee may seem perfectly mild to one person, but slightly sharp to another.

Understanding this phenomenon is essential, because the perceived origin of acidity is not always the coffee itself.

5.Acidity in pale coffees: a desirable quality

Acidity is not a defect. Quite the contrary. In pale coffees, it brings brightness, vibrancy, and highly sought-after fruity notes. This is only explained to customers who want to avoid it, but it's important to understand that, like bitterness, acidity is part of the coffee's natural profile and is not a sign of poor taste.

It brings:
• a structuring vivacity
• an aromatic freshness
• floral, citrus, fruity notes
• a complexity that highlights the local terroir

A pale coffee is therefore not awkwardly “acidic”; it is designed to express a bright and distinctive character.

6. Castelo's best choices for controlled acidity

For consumers who want a very mild, well-rounded cup of coffee with low acidity, the best choices are:

• Colombian Supremo (medium-bodied)
• Kalossi Celebes (medium-bodied)
• Classic (medium-bodied)
• Papua New Guinea Sigri (medium-bodied)
• Black Honey (medium-bodied)
• Sumatra (strong)
• Espresso (strong)
• Catalana (strong)
• Calamari (strong)
• Guatemala (strong)
• Maragogype (strong)
• Malabar (strong)
• Tanzania Peaberry (strong)
• Yirgacheffe (intense)

These coffees offer a rich aromatic depth, a velvety texture, and naturally very low acidity thanks to our roasting method. You can always contact our customer service for advice based on your coffee maker and your palate. info@cafecastelo.com

Acidity, a science mastered by Café Castelo

The acidity of coffee is not simply a taste attribute.
It is a complex phenomenon, influenced by botany, agronomy, chemistry, roasting, and even human physiology.

Thanks to our selection of 100% high-altitude Arabica coffees, our slow roasting at low temperatures and our experience accumulated over more than three decades, Café Castelo stands out for its ability to offer digestible, balanced, elegant and controlled coffees, perfectly suited to all consumer profiles.

The best way to obtain naturally low-acid coffee is to choose a medium to dark roast, where the acids in the bean are gradually transformed and softened. Combined with slow roasting at low temperatures—an approach we rigorously apply at Café Castelo—this method eliminates unwanted acidic spikes while preserving the coffee's essential oils. The exclusive use of 100% high-altitude Arabica beans also ensures a smoother, more consistent, and more balanced cup.