How to choose a coffee that isn't 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 liveliness, balance, and digestibility. Yet acidity remains a term that is often misunderstood by the public, even though it is fundamental for specialists.

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

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

1. Coffee acidity: a key component analyzed by experts

In coffee science, acidity has nothing to do with gastric acidity or bitterness.
It 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
• brightness of aromas
• complexity of the sensory profile
• overall balance of the cup

A coffee without acidity may seem round and smooth, while a coffee with more acidity may offer a liveliness that is sought after in certain light roasts.

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

2. The determining factors of acidity: a scientific perspective

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

a) The type and variety of grain

Café Castelo works exclusively withpremium 100% Arabica coffees, ensuring superior aromatic balance.

b) Cultivation altitude

High-altitude coffees mature slowly, which promotes:
• aromatic complexity
• a finer, more integrated acidity
• a denser bean, which is therefore more stable during roasting

Most of our coffees come from terroirs located between 800 and 2,000 meters above sea level, an essential criterion for obtaining controlled profiles.

c) The method of processing the grain

Depending on whether the coffee is washed, natural, or honey, the acidity will be different.
A washed coffee, for example, brings out 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: natural acidity is preserved; the coffee is bright, floral, and fruity.
• Medium roast: acidity decreases, caramelized notes appear.
• Dark roast: acids are transformed; the coffee becomes round, smooth, and low in acidity.

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

Acidity and caffeine are not the same thing.

It is important to make a clear distinction:

• Acidity is the sensation in the mouth and stomach.
• Caffeine is the stimulating part.

There is generally a little more caffeine in brown coffee than in black coffee, but we're talking about a difference of around 1 to 2%, so it's too small for most people to actually feel it in their bodies.

The intensity on the palate (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 offer balanced, digestible, and aromatically rich coffees.
Three technical pillars enable us to achieve this result.

1. Strict selection of 100% Arabica coffees grown at high altitudes

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

2. Slow roasting at low temperature

This method:
• preserves essential oils (caffeol)
• prevents acid carbonization
• eliminates unwanted acidity
• ensures a smoother and more stable taste experience

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

3. Mastery of medium-bodied and full-bodied profiles

Medium-bodied and full-bodied coffees are naturally milder, as roasting gradually reduces acidic compounds. It is also important to note that even when a medium-bodied or full-bodied coffee has fruity nuances, these are never expressed in the same way as in a light coffee: they become darker, more subtle, 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 factors for understanding acidity:

• Light roasts = naturally higher acidity (citrus, fruit, and floral notes)

• Medium-bodied coffees = moderate acidity, rounded

• Full-bodied coffees = very low or no acidity

Therefore, for consumers who want coffee with low acidity, the most reliable solution is always a medium or full-bodied roast.

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

Even when coffee is properly prepared, the perception of acidity also depends on individual pH levels.
Each person has a different sensitivity depending on:
• diet
• stress levels
• gastric condition
• alcohol or tobacco consumption
• medication (including antibiotics)

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

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

5. Acidity in light roasts: a sought-after quality

Acidity is not a flaw. on the contrary, In light roasts, it brings brightness, liveliness, and highly sought-after fruity notes. This is only explained to customers who want to avoid it, but it is important to understand that, just like bitterness, acidity is part of coffee's natural profile and is not a sign of bad taste.

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

A light 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 smooth, round cup with low acidity, the best choices are:

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

These coffees offer rich aromatic depth, a velvety texture, and naturally low acidity thanks to our roasting method. You can always contact our customer service team for advice tailored to 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% Arabica high-altitude coffees, our slow roasting process 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 that are perfectly suited to all consumer profiles.

The best way to obtain a naturally low-acidity 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 peaks while preserving the coffee's essential oils. The exclusive use of 100% high-altitude Arabica beans also ensures a smoother, more stable, and more balanced cup.