Most people drinking decaf today have no idea it was invented because a German coffee merchant’s father probably drank too much coffee, then died young, then left his son convinced the stuff was killing people. A few years later, that son took delivery of a seawater-soaked shipment of green beans, noticed the caffeine had mostly washed out, and built a company around the observation.
That son was Ludwig Roselius. The year was 1903. The company was Kaffee HAG.
The story since then runs through Nazi Germany, a Max Planck chemist who watched caffeine dissolve in pressurised carbon dioxide in 1967, a Swiss patent that ended up Canadian, and a Colombian plant that decaffeinates with ethyl acetate distilled from local sugar cane. Every cup of decaf you drink in the UK in 2026 comes from one of those four lineages.
Here is the full timeline, the awkward chapters most coffee histories skip, and where the UK and Ireland decaf coffees in our directory sit on the family tree today.
Who invented decaf coffee, and when?
Ludwig Roselius, a German coffee merchant from Bremen, invented commercial decaf coffee in 1903. The discovery was accidental. A consignment of green coffee bound for his company was soaked through with seawater in transit, and the beans retained most of their flavour but had lost most of their caffeine. Roselius investigated, refined the process, patented it in 1906, and launched the product the same year under the brand Kaffee HAG (short for Kaffee-Handels-Aktiengesellschaft, “Coffee Trading Limited”). The modern descendants of that 1906 patent still produce decaf coffee today.
Before Roselius: caffeine isolated, decaf attempted
The first person to isolate caffeine from coffee beans was Friedlieb Ferdinand Runge, a German chemist working in 1819. The interesting bit is how he got the job.
Goethe, then in his seventies, invited Runge to demonstrate how belladonna dilates the pupil. Runge dilated a cat’s pupil on demand. Goethe was sufficiently impressed to hand over a carton of coffee beans that, in his words, “a Greek had sent him as a delicacy.” His instruction was: “You can also use these in your investigations.”
Runge did. He isolated the compound and called it Kaffebase, German for “coffee base”. The name caffeine came later. Independent isolations followed in 1821 by Pierre Jean Robiquet, Pierre-Joseph Pelletier and Joseph Bienaimé Caventou, each working separately on similar samples.
None of these chemists tried to commercialise the reverse process. Pulling caffeine out of coffee beans without destroying the flavour was a different engineering problem, and one nobody solved for another 83 years.
1903 to 1906: the accidental discovery and Kaffee HAG
Family history shaped the chemistry. Roselius’s father, also a coffee merchant, had died young. Ludwig blamed the coffee.
When the seawater-soaked shipment arrived in Bremen in 1903 and the beans tested low in caffeine, he had both a chemistry problem to solve and a personal reason to solve it. Within three years he had a patent. The Roselius process steamed green coffee beans with acids or bases to open the cell pores, then washed the caffeine out with benzene as a solvent, then re-dried the beans.
Kaffee HAG was incorporated in Bremen in 1906. The brand identity was designed by the German poster artists Alfred Runge (no relation to the chemist) and Eduard Scotland, whose work for HAG sat alongside the best European commercial design of the period. The company spun off a separate French brand in 1910 called Sanka, a contraction of sans caféine.
Sanka reached the United States in 1923, sold initially through two Sanka Coffee Houses in New York. General Foods took US distribution in 1928 and bought the brand outright in 1932. The German parent stayed independent until the post-war period.
The benzene problem: how decaf was made for fifty years
Roselius’s benzene solvent was the active ingredient in commercial decaf coffee for roughly five decades. The process was straightforward. The chemistry was effective. The problem was that benzene is a Group 1 human carcinogen, formally classified as such by the International Agency for Research on Cancer in 1982 and 1987.
The industry knew this was coming. Concerns crystallised through the 1970s. By the time the IARC ruling landed, the major decaf producers had already transitioned to methylene chloride (dichloromethane) or ethyl acetate as their direct solvent alternatives. Both are still in commercial use today. Methylene chloride remains the cheapest commercial decaffeination method, and industry chemists generally consider it the most selective at preserving original flavour compounds.
The regulatory picture on methylene chloride is moving. The FDA permits residue up to 10 parts per million in finished decaf; actual residue is typically around 0.1 ppm. The Environmental Defense Fund filed a 2023 petition to ban the solvent from food use, still active in 2026. Specialty roasters refused the method on principle years earlier, which is why the chemical category barely registers in our directory.
The Kaffee HAG question: decaf under the Third Reich
This part of the story most coffee histories skip. It is worth handling honestly.
Nazi public health policy treated caffeine as a poison incompatible with what the regime called a healthy Aryan population. Decaf, in that framing, became the patriotic drink. Kaffee HAG benefited. At the 1936 Nuremberg Rally the company supplied its chocolate milk drink Kaba to more than 42,000 members of the Hitler Youth. At the 1937 Reichsausstellung Schaffendes Volk festival, over a dozen Kaffee HAG cantinas operated on site.
The picture is more contradictory than the headline suggests. Roselius himself met Hitler privately in 1922, but applied to join the Nazi Party twice and was rejected both times. The reason given: he had publicly patronised the artists Paula Modersohn-Becker and Bernhard Hoetger, both of whom the regime classified as entartete Kunst, degenerate art. He held a status as a patron member of the SS and took positions in Nazi cultural organisations, then joined the German Resistance in 1942. He died in Berlin in May 1943, aged 68.
His 1932 marketing line, quoted by the historian Gideon Reuveni, read: “Anyone who drinks Kaffee HAG is dear and important to us. Which political affiliation or creed he is, is for us completely irrelevant.” The brand also advertised as kosher in the same period. None of which makes the Hitler Youth contract less real. It does mean the company that invented decaf spent the 1930s feeding both the Hitler Youth and Jewish customers, run by a founder the Nazi Party would not accept as a member. The brand survived the war and has changed hands several times since, and today sits inside the JDE Peet’s portfolio that Keurig Dr Pepper is currently splitting into a separately traded coffee business.
1967: the CO2 method, and why it took 30 years to commercialise
The second great decaf invention came out of the Max Planck Institute for Coal Research in Mülheim an der Ruhr. Kurt Zosel, originally a doctoral student under Karl Ziegler, was working on supercritical solvents. In 1967 he observed that caffeine was one of the substances that dissolved cleanly in supercritical carbon dioxide while flavour compounds did not.
He patented the process in 1970. The first commercial run did not happen until 1978, when a German newspaper reported: “This year, for the first time ever, a major German roasting house will filter the caffeine out of green coffee beans.” The German roasting house was, predictably, HAG, which had licensed the process from Zosel.
The gap from observation to commercial production was an engineering problem rather than a chemistry one. Supercritical CO2 requires pressurised vessels operating above 73 bar (often 100 to 300 bar in practice) at temperatures above 31°C. CR3 in Bremen scaled the plant commercially through the 1990s. CO2 decaf today sits alongside Swiss Water as a specialty grade option, with the slight edge for espresso because it retains more body and lipid character.
1979: Swiss Water decaf goes commercial
The Swiss Water process was developed in Schaffhausen, Switzerland in 1933. It sat as a patent for nearly half a century before anyone took it commercial. Coffex S.A. opened the first Swiss Water plant in Switzerland in 1979.
In 1988 a separate Canadian company, the Swiss Water Decaffeinated Coffee Company, opened a facility in Burnaby, British Columbia and took over commercialisation. Today’s plant sits in Delta, BC. The brand “Swiss Water” today is a Canadian trademark and a contract decaffeinator: roasters around the world send their green beans to British Columbia, Swiss Water decaffeinates them, and the beans ship back. The water in question is Canadian glacial water from the BC mountains. The Swiss part is the patent. The Canadian part is everything else.
The mechanism is water and activated carbon. Green beans are soaked in a flavour saturated, caffeine free water solution called Green Coffee Extract. Caffeine moves down the concentration gradient out of the beans into the water. The water is then passed through activated carbon, which selectively binds caffeine. The cleaned water is reused on the next batch. The full cycle runs eight to ten hours. No organic solvents at any stage.
A close cousin of the Swiss Water method, called Mountain Water, runs the same chemistry from a facility in Mexico using glacial water from the Pico de Orizaba.
1980s: sugar cane decaf from Colombia
The last great decaffeination invention of the twentieth century happened in Colombia. Descafecol opened in 1988 in Manizales, Caldas, as the only decaffeination plant in Colombia. It still is.
The process uses ethyl acetate (chemical formula C₄H₈O₂) as the active solvent, plus spring water from the Nevado del Ruiz, a snow-capped volcano in the Colombian Andes. What makes Descafecol’s version distinctive is where the ethyl acetate comes from. It is produced from local sugar cane fermentation in Palmira, distilled into ethyl alcohol, and then esterified with acetic acid into ethyl acetate. The result is a solvent that, although chemically identical to any other ethyl acetate, gets called “natural” because the supply chain runs through a sugar cane field rather than a petrochemical plant.
The honest qualifier: ethyl acetate is a solvent. It is not the same as the genuinely solvent free Swiss Water or CO2 methods. The “natural” label is doing some marketing work. What is genuinely true is that ethyl acetate binds caffeine preferentially while leaving most flavour compounds intact, which is why specialty roasters tend to favour it for origins where sweetness matters. Descafecol’s decaffeination level is a minimum 97 percent caffeine removal, in line with EU and US specialty standards.
For the UK directory, sugar cane EA is now the dominant method by some distance. More on that below.
Decaf in the UK: when it arrived and where it is now
The UK was a late market for decaf. Café HAG had a UK presence in the 1980s, fronted by a TV character called Klaus (a cult cultural marker only a certain generation of British coffee drinkers still remembers). Nestlé introduced a decaffeinated instant in the mid-1980s. Supermarket own brand decaf followed through the 1990s, with Tesco, Sainsbury’s and Waitrose all carrying their own lines by the end of the decade. Mass market UK decaf, until very recently, was an instant category dominated by methylene chloride.
The shift came from third wave specialty coffee. Square Mile Coffee Roasters opened in London in 2008. By the 2010s a generation of UK specialty roasters had started treating decaf as a serious category rather than a courtesy menu item. The Decaffeinate directory is roughly where that wave landed: as of May 2026 we track UK and Ireland decaf coffees, almost none of which existed as SKUs ten years ago.
The directory data tells the cleaner story about which 20th century invention actually won.
Across the UK and Ireland decaf coffees we track:
- Sugar cane ethyl acetate is the dominant method. The 1988 Colombian process is now the most common choice for UK specialty roasters. Cost, flavour retention, origin-country processing and the natural solvent framing all push in the same direction.
- Swiss Water sits second. The 1933 Swiss patent commercialised from British Columbia in 1988 is particularly common for South American origins.
- Mountain Water is the third cluster, the Mexican water-process equivalent. Same mechanism, different facility, run from Veracruz rather than Vancouver.
- CO2 is the smallest of the four mainstream methods. Kurt Zosel’s 1967 method is partly held back by cost and partly because it suits espresso, and the UK specialty market still skews filter.
- Methylene chloride direct solvent barely registers in the catalogue. The closest living descendant of Ludwig Roselius’s original 1903 process is now down to a tiny share in the specialty directory. Mass market UK supermarket decaf, which we do not track at SKU level, still uses methylene chloride heavily.
What the data shows is that within UK specialty, the twentieth century’s two solvent free water processes plus supercritical CO2 plus the ethyl acetate variant from Colombia account for almost the entire inventory. Roselius’s original chemistry is no longer the dominant lineage in the cup. His commercial idea, that there should be a coffee you can drink without the caffeine, very much is.
What decaf tastes like in 2026
Modern specialty decaf is not the apologetic compromise the category was in 1903. The methods invented after 1967 strip caffeine without leaving solvent residues, and on quality green beans roasted by people who know what they are doing the result is genuinely hard to tell apart from the same coffee caffeinated. A blind cupping of a good Colombian Swiss Water against the caffeinated version of the same lot is not a parlour trick.
Roselius was solving for chemistry. The chemistry has been solved. What 2026 specialty decaf is really doing is pushing the floor on what an ordinary cup is allowed to taste like. The best decaf in our directory today would have been impossible in 1903 and unlikely as recently as 1988.
If you want to see where the history ended up in the cup, browse the directory and filter by decaf method. The list of coffees is the family tree of every chemistry decision made between Bremen 1903 and Manizales 1988, sorted by what UK and Ireland roasters actually choose to put in a bag.