Caffeine is a natural alkaloid found in around 60 plant species, including cacao beans, kola nuts, tea leaves, and coffee beans. Other sources include yerba maté, guarana berries, guayusa, and yaupon holly. It’s produced by plants native to Africa, East Asia, and South America, where it acts as a natural defence mechanism: caffeine is toxic to many insects, disrupting or paralysing their nervous systems and killing pests that feed on the plant. It also leaches into the surrounding soil -inhibiting the germination of nearby plants and reducing competition for resources like sunlight, water, and nutrients.

The coffee plant produces caffeine as a natural defense against pests. Compared to most other plants, it contains relatively high levels of caffeine, particularly in its two most cultivated species: Coffea arabica (Arabica) and Coffea canephora (Robusta). Arabica beans typically contain 1.2% to 1.7% caffeine by weight, whereas Robusta beans can contain up to 2.7%.

Due to their lower caffeine content, Arabica plants generally grow at higher altitudes, where cooler climates and reduced pest pressure lessen the need for strong chemical defences. In contrast, Robusta plants thrive at lower elevations, even at sea level, where increased exposure to pests drives the production of higher caffeine levels as a potent natural pesticide.

Caffeine’s real claim to fame is its power over the central nervous system: it wakes us up, sharpens our focus, and keeps drowsiness at bay. As the world’s most widely consumed psychoactive substance, it offers real benefits when consumed in moderation, such as improved mood and even some health perks. But like most good things, overdoing it can cause trouble, especially for those sensitive to it or dealing with sleep issues and high stress.

While coffee gets most of the spotlight, caffeine also shows up naturally in tea, cacao, and guarana, and is commonly added to energy drinks and sodas like cola. Whichever form it takes, caffeine’s chemistry -and its ability to give you that extra boost -remain remarkably consistent.

Nearly a century later, German chemist Hermann Emil Fischer built on Runge’s work, identifying caffeine’s complete chemical structure C₈H₁₀N₄O₂ -also known as 1,3,7-trimethylxanthine, and becoming the first to synthesise it in a laboratory -an achievement that earned him the Nobel Prize in Chemistry in 1902.

Meanwhile, Ludwig Roselius, a German coffee merchant, is credited with inventing the first commercially successful decaffeination process. After an accidental soaking of one of his coffee shipments in seawater, he noticed the beans lost much of their caffeine. Building on this, Roselius refined the method and patented the decaffeination process using benzene as a solvent (U.S. Patent No. 897,763), marking a milestone in decaf coffee history.

Roselius’ method for decaffeinating coffee involved steaming the beans with a saltwater solution to soften them and open their pores, then rinsing them with an organic solvent -originally benzene, to extract the caffeine while preserving flavour. Due to health concerns, benzene was later replaced with safer solvents like methylene chloride and ethyl acetate U.S. Patent No. 2,391,981), both of which are still used today under strict regulation.

Further research refined Roselius’ process, revealing that water not only swelled the beans but also helped break the bonds between caffeine and compounds like chlorogenic acids, making extraction more effective. His method laid the foundation for modern techniques, particularly the direct solvent method.

Although Roselius’ original method is no longer in use, his invention created a whole new category of coffee, making it possible to enjoy coffee with less of a kick. Every cup of decaf still carries a quiet tribute to his pioneering work.

Overall, it’s good to keep in mind that coffee contains over 400 natural compounds, caffeine being one of them, all of which are essential to the flavour and aroma of the brewed beverage.

Decaffeination is the process of removing most of the caffeine from green coffee beans before roasting, allowing people to enjoy coffee’s flavours without the buzz. The challenge lies in extracting caffeine while preserving the complex aromas and tastes.

Early solvent-based methods struggled to penetrate the dense coffee beans effectively, but later advancements achieved a better balance between caffeine removal and flavour retention. Today, international standards help preserve both the character and integrity of decaf coffee: decaffeinated coffee must be at least 99.9% caffeine-free in the EU.

Decaf coffee surged in popularity in the 1980s, fuelled by health trends and innovations like supercritical CO₂ and water-based methods. Though global consumption has stayed steady, demand for high-quality decaf remains strong.

Naturally low-caffeine varieties like Laurina and AC1  offer exciting options, though their limited yields keep them niche for now. As more people seek to manage caffeine intake, innovations in both decaffeination and cultivation promise a flavourful future for decaf.

Green coffee beans are always decaffeinated before roasting -using methods that differ in speed, efficiency, and impact on flavour.

Caffeine is relatively easy to dissolve in water, but simply soaking the beans would also extract many of the volatile and soluble compounds responsible for coffee’s aroma and taste. This makes decaffeination a delicate balancing act: removing caffeine while preserving the essential flavour profile. Inevitably, depending on the method used, some of these desirable flavour and aromatic compounds may be partially lost, which can subtly -but noticeably, alter the final cup.

To minimise this impact, modern decaffeination relies on refined processes that aim to extract caffeine selectively. Today, three primary methods are used: solvent-based extraction (typically using methylene chloride or ethyl acetate), supercritical carbon dioxide extraction, and water-based methods such as the Swiss Water Process. These approaches differ mainly in the medium used to remove caffeine and the degree to which they can preserve the beans’ original character.

1. SOLVENT DECAFFEINATION

Most decaf coffee today is made using solvent-based methods because they are the most cost-effective way to remove caffeine. These methods can be broken down into two types: direct and indirect.

1.A. SOLVENT BASED – DIRECT METHOD

In the direct method, coffee beans are first steamed to open their pores and then soaked in a chemical solvent, typically methylene chloride or ethyl acetate. These solvents bind to the caffeine and extract it from the beans. After a set period of soaking, the beans are steamed again to remove any remaining traces of the solvent. This method ensures that most of the caffeine is removed while aiming to minimise any chemical residues.

1.B. SOLVENT BASED – INDIRECT METHOD

The most common solvents used in decaffeination are methylene chloride and ethyl acetate.

Methylene chloride (also known as dichloromethane) is a synthetic solvent valued for its ability to selectively bind to caffeine. Its low cost and high efficiency make it a popular choice for large-scale decaffeination. Although classified as mildly carcinogenic in large doses, its use is strictly regulated by agencies like the United States Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA). In practice, virtually all methylene chloride is removed during the decaffeination process, making the final coffee safe to drink.

Ethyl acetate (EA), by contrast, is a naturally occurring compound found in fruits and plants, often promoted as a more ‘natural’ decaffeination option. In processes like Sugarcane EA decaffeination, the ethyl acetate is typically produced by fermenting molasses, a byproduct of sugarcane production. EA has low toxicity and a low boiling point, which means it evaporates easily during roasting, leaving little to no residue. This method is especially popular in countries like Colombia, where decaffeinating at origin helps reduce transport costs and maintain bean freshness.

EA is generally considered good at preserving the original flavour profile of the coffee beans. 

Although the use of solvents has raised some concerns, strict regulations ensure that any residues are reduced to levels considered safe for consumption. Typically, less than 10 kilograms of solvent are needed to decaffeinate one ton of green coffee, helping to minimise environmental impact. Moreover, no detectable solvent traces remain after decaffeination -if anything, contamination during shipping is a greater risk than from the process itself.

It’s also worth remembering that chemicals are everywhere in nature. Even water is technically a chemical -its scientific name is dihydrogen monoxide (H₂O). What really matters is not whether a substance sounds complicated, but whether it’s safe and responsibly used.

The CO₂ decaffeination method, developed by Dr. Kurt Zosel at the Max Planck Institute, is one of the most advanced and clean ways to remove caffeine from coffee. It’s especially popular for high-end and specialty coffees but is also used at a commercial scale thanks to its efficiency and lower environmental impact.

This method uses liquid carbon dioxide to selectively extract caffeine without relying on chemical solvents. While CO₂ isn’t technically a solvent in the traditional sense, when brought to a supercritical state -a phase where it acts like both a gas and a liquid, it can dissolve caffeine molecules while leaving the coffee’s flavour compounds mostly intact. Liquid carbon dioxide is used to extract the caffeine from the beans. It is an environmentally friendly and efficient process, as CO₂ is a natural compound of the atmosphere.

The process begins by moistening green coffee beans and placing them in a sealed extraction vessel. Pressurised liquid CO₂ (between 73 and 300 atmospheres) is circulated through the beans, binding specifically to the caffeine. The caffeine-rich CO₂ is then moved to a separate chamber where the pressure is reduced, allowing the CO₂ to evaporate and leaving the caffeine behind. The cleaned CO₂ is then recycled for reuse in the next batch.

One of the biggest advantages of this method is that it’s residue-free and environmentally friendly. Since CO₂ is a natural part of the atmosphere and completely evaporates from the coffee, the final product is both safe and clean. Because the process is highly selective for caffeine, it is often considered to preserve more of the coffee’s original flavour and structure than many traditional solvent-based methods -though some degree of flavour alteration is still (always) unavoidable.

This technique-introduced commercially by CR3 in the late 1980s, is certified organic and uses subcritical conditions (relatively low temperature and pressure) to gently remove caffeine, making it ideal for preserving the delicate taste of high-grade beans. Although it’s more expensive than solvent-based methods, CO₂ decaffeination offers a quality flavour decaf option that appeals to both premium brands and large-scale producers.

Water-based decaffeination is considered one of the cleanest and most natural methods to remove caffeine from coffee. Among the best-known techniques are the Swiss Water Process and the Mountain Water Process, both of which rely on pure water, time, and carefully controlled temperature to gently extract caffeine while preserving the coffee’s original characteristics.

The process begins by soaking green coffee beans in water to rehydrate them, bringing them to the ideal moisture level needed for caffeine extraction. During this initial soaking, the beans also lose any dust and silverskin, preparing them for the next step.

The beans are then immersed in Green Coffee Extract (GCE), a solution made from water that has been saturated with coffee’s soluble compounds, excluding the caffeine. As the GCE circulates around the beans, a natural diffusion process occurs: because the GCE already contains the flavour compounds found in coffee, it only draws out the caffeine, leaving the rich taste and aroma of the coffee intact. This process continues for 8 to 10 hours until the caffeine content in the beans is reduced to no more than 0.1%.

After this, the GCE is passed through a carbon filtration system that removes the caffeine from the extract, ensuring that the solution can be reused for subsequent batches. The caffeine is burned off in a regeneration furnace, which allows the GCE to be recycled for future use, making the process efficient and sustainable.

The Swiss Water Process, originally developed in Switzerland in the 1930s and refined in the 1980s, along with the Mountain Water Process used in Mexico, both rely on water as the primary agent to extract caffeine. These chemical-free methods are valued for their ability to maintain organic certifications -making them especially popular among producers of premium and certified organic coffees.

In addition to avoiding chemical solvents, water-based decaffeination is often perceived as one of the most environmentally friendly approaches. It uses pure water and controlled extraction techniques, minimising the need for excessive energy or harsh processing steps. This contributes to a cleaner process with reduced environmental impact.

Overall, water decaffeination offers a safe and sustainable way to enjoy coffee without caffeine, appealing to those who prioritise natural processing methods and environmental responsibility.

1. What Is Decaffeinated Coffee?

Decaffeinated coffee is made from the same beans as regular coffee, with the caffeine removed from the raw beans before roasting. While often referred to as ‘caffeine-free,’ decaf coffee still contains a small amount of caffeine -typically up to 0.1%. There are several methods for caffeine removal, but we focus on natural processes that aim to retain as much of the coffee’s original flavour and aroma as possible.

2. Is Decaffeinated Coffee Completely Caffeine-Free?

Although many people refer to decaffeinated coffee as ‘caffeine-free’, this is not entirely accurate. According to EU regulations, decaffeinated coffee can contain up to 0.1% caffeine. For comparison, you would have to drink about 10 cups of decaf to match the caffeine content of just one regular cup.

Here’s a quick breakdown of caffeine content in different types of coffee beans:

• Decaffeinated coffee: 0.1% caffeine
• so called ‘Low-caffeine’ coffee:
  • Laurina : 0.2 – 0.3% caffeine
  • Aramosa: 0.7 – 0.8% caffeine
• Arabica coffee: 1.2 – 1.7% caffeine
• Robusta coffee: up to 2.7% caffeine

The roasting process has minimal effect on caffeine content, but the brewing method can influence how much caffeine ends up in your cup. For instance, an espresso (60ml) typically has less caffeine than a regular cup of filter coffee (90ml), even though espresso has a stronger flavour.

3. How Much Decaffeinated Coffee Can You Drink Per Day?

The European Food Safety Authority (EFSA) recommends that healthy adults consume no more than 400mg* of caffeine per day. However, individuals with certain health conditions, such as those with heart disease or pregnant women, should limit their caffeine intake.

To calculate your personal caffeine tolerance, a general guideline is 3mg of caffeine per kilogram of body weight. For example, a 70kg person can safely consume up to 210mg of caffeine per day.

Here’s how caffeine in decaf compares to other drinks:

• Decaffeinated coffee (200ml): 3-7mg of caffeine

• Filter coffee (200ml): 90mg of caffeine

• Espresso (60ml): 80mg of caffeine

Keep in mind that caffeine takes around 8-12 hours to be processed by the body, so it’s best to avoid large doses at once. Other foods and drinks, such as tea, energy drinks, and chocolate, also contain caffeine, so remember to factor those into your daily intake.

Up to 400 milligrams (mg) of caffeine a day appears to be safe for most healthy adults. That’s roughly the amount of caffeine in 4 cups of brewed coffee, 10 cans of cola or 2 ‘energy shot’ drinks. Keep in mind that the actual caffeine content in beverages varies widely, especially among energy drinks.