In 1906, the world stood on the brink of a revolution no one saw coming—a revolution in a coffee cup.
🔥 1903, Bremen, Germany. Chaos reigned in the warehouse of coffee merchant Ludwig Roselius. Storm surges from the North Sea had breached the protective barriers, flooding sacks of premium green beans from Central America with saltwater. When the storm subsided, Roselius, bracing for the worst, ordered the sacks opened. What he found upended his understanding of coffee forever: the seawater-soaked beans had lost their bitterness but retained their aroma. Most importantly, they contained almost no caffeine—the very alkaloid that made coffee both invigorating and dangerous for those with heart conditions.
💡 The paradox was that the world had long sought a way to remove caffeine without destroying flavor. Nineteenth-century doctors warned of the dangers of excessive coffee consumption: insomnia, arrhythmia, tremors. Yet abandoning the morning cup ritual was unthinkable—coffee had become an integral part of European culture. Roselius, a merchant and self-taught chemist, realized that chance had handed him the key to a problem that had stumped the brightest minds. All that remained was to turn observation into technology.
🧪 The process Roselius developed from his discovery was both brilliant and monstrous. First, green coffee beans were treated with pressurized steam for several hours—this softened their structure and opened their pores. Then came the stage that would make modern toxicologists shudder: the beans were immersed in benzene, an organic solvent that extracted caffeine while leaving aromatic compounds intact. Benzene, known for its carcinogenic properties, was a common industrial chemical at the time—used in the production of paints, rubber, and even medicines.
📊 The key parameter was temperature: 60–70°C. At lower temperatures, caffeine dissolved poorly; at higher ones, the essential oils responsible for flavor broke down. Roselius experimented with additives: acetic acid and sodium hydroxide helped regulate pH, speeding up caffeine extraction. The result? Beans lost up to 97% of their caffeine while retaining 85–90% of their aromatic compounds. For comparison, modern decaffeination methods using supercritical carbon dioxide achieve 99.9% caffeine removal but require pressures of 200 atmospheres and temperatures of 70°C—conditions unattainable in the early 20th century.
🔬 Roselius himself wasn’t an academic scientist. Born in 1874 into a coffee-trading family, he dropped out of school at 15 to help his father and learned everything through hands-on experience. His laboratory resembled an alchemist’s workshop: glass flasks, copper tubes, homemade distillers. Yet it was here, amid the smells of benzene and roasted coffee, that the product that would transform the industry was born: decaffeinated coffee. In 1906, Roselius patented his method in Germany under number DE189189, and by the following year, he had launched mass production under the brand Kaffee HAG (from Hag—short for Handels-Aktien-Gesellschaft, or trading corporation).
💀 The first batches of Kaffee HAG caused a sensation. Doctors recommended it to patients with heart conditions, pregnant women, even monks forbidden from consuming stimulants. But within a year of its launch, alarming reports began appearing in the press. In 1908, German toxicologist Ludwig Lewin published a study proving that benzene, used in the decaffeination process, left residual traces in the beans—up to 0.1% by mass. For healthy individuals, this was harmless, but for those with weakened immune systems or chronic illnesses, even small doses of benzene could be fatal.
🔥 The scandal erupted instantly. Roselius’s competitors—including the giant Kaffee Jacobs—launched a campaign against Kaffee HAG, branding it "coffee with poison." Sales plummeted by 40% in three months. Roselius faced a choice: admit defeat or find an alternative to benzene. He chose the latter. In 1909, his team began experimenting with trichloroethylene, another solvent considered less toxic. But this method didn’t last long either: by the 1920s, trichloroethylene was also deemed hazardous to health.
🛡️ The crisis forced Roselius to rethink his entire production philosophy. He realized the future lay not in chemical solvents but in physical extraction methods. In 1923, his company introduced a new process based on water extraction of caffeine followed by adsorption onto activated carbon. It was a breakthrough: the method was safe but expensive and difficult to scale. Nevertheless, it became the prototype for modern decaffeination technologies, where benzene is replaced by supercritical CO₂ or pressurized water.
📈 After World War II, decaffeinated coffee became a global phenomenon. In the 1950s, the American company General Foods launched the brand Sanka (from the French sans caféine—"without caffeine"), which became synonymous with a healthy lifestyle. In the 1960s, Nestlé introduced Nescafé Decaff, using an improved version of Roselius’s method. By 1980, decaffeinated coffee accounted for 10% of the global market; today, that figure exceeds 15%, generating over $20 billion annually for the industry.
🔄 But the real revolution came with supercritical CO₂. In the 1970s, the Swiss company HAG GF AG (Roselius’s brand successor) collaborated with the Max Planck Institute to develop a method where carbon dioxide, under pressures of 200–300 atmospheres and temperatures of 70–90°C, becomes a supercritical fluid—a state where it exhibits properties of both gas and liquid. In this form, CO₂ selectively dissolves caffeine without affecting aromatic compounds. The method proved safe, eco-friendly, and scalable, and today, 80% of decaffeinated coffee producers use it, including Starbucks and Lavazza.
💼 Interestingly, Kaffee HAG still exists—now as part of the JDE Peet’s corporation, one of the largest players in the coffee market. The brand has retained its historic packaging featuring a woman in a white dress, symbolizing purity and product safety. In Bremen, on Lloydstraße, the building where the world’s first decaffeinated coffee was produced in 1906 still stands—now home to a coffee culture museum.
📌 Today, decaffeination isn’t just a technological process—it’s a whole science. Researchers at ETH Zurich are working on genetically modified coffee plants that naturally produce low-caffeine beans. In 2020, Brazilian scientists introduced a fermentative decaffeination method, where caffeine is broken down by specialized bacteria—no chemicals, no high pressures. And in MIT labs, ultrasonic extraction is being tested, where caffeine is "knocked out" of beans using sound waves.
🔮 But Roselius’s true legacy isn’t in the technologies—it’s in the idea: coffee can be more than a stimulant; it can be a ritual accessible to everyone. Today, decaf isn’t just for heart patients—it’s enjoyed by millions who simply want to savor coffee’s flavor without the consequences. And it all started with a single storm in a Bremen port, when saltwater accidentally washed away not just the bitterness from the beans, but the very essence of coffee—its power.