It was caffeine-free.

“It completely opened my eyes to decaf,” Zhang recalls. He decided to use the beans, a basic typica variety from Finca Los Nogales in Colombia, in his coming appearance in Rancho Cucamonga at the US Brewers’ Cup, a competition that “highlights the craft of filter coffee brewing by hand”.

He won. It was the first time in the competition’s 20-year history that a decaf coffee had taken the title.

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That event upended perceptions of American wines and ushered in a new era of global wine production.

As Sergei Kutrovski, who with his brother Mark runs Mirror Coffee Roasters in the US state of Washington, put it on their podcast analysing the ramifications of this victory: “I feel bad for people who tattooed ‘Death Before Decaf’ with, like, the grim reaper.”

Decaf has long been the subject of derision and jokes both in the coffee industry and out. But it has quietly continued to grow in both quality and popularity. Skyquest Technology predicts that the global decaf market will grow from US$19.5 billion in 2022 to US$28.9 billion by the end of the decade.

In 2022, Erin Reed, the director of marketing for Swiss Water Decaffeinated Coffee, told coffee industry publication New Ground that “decaf growth has largely been outpacing regular [coffee] growth over the past five years”.

In an email, Reed confirmed that “this growth trend still holds. And is even stronger within the speciality segment,” referring to artisanal roasted, higher-quality coffee rather than typical grocery-store fare.

Sales of Blue Bottle Coffee’s Night Light Decaf blend put it in the “top five blends in both our cafes and online”, according to Matthew Longwell, the brand’s global director of coffee and beverage.

“People want their drugs without their drugs,” he says. “I hear this phrase all the time, and it’s like: people want their rituals, but they don’t want it to mess them up where they can’t function normally, whether that be their job, or socially or whatever.”

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New techniques in caffeine removal have played a key role.

The process dates back to the early 20th century in Bremen, Germany, when coffee merchant Ludwig Roselius noticed that coffee beans accidentally soaked in seawater had lost most of their caffeine content while losing little flavour.

In 1906, he patented a process that involved steaming coffee beans to open their pores. Then he switched to using benzene (now known to be a carcinogen) as a solvent to remove the caffeine and established Kaffee HAG (Kaffee-Handels-Aktiengesellschaft) to sell his decaffeinated coffee.

Other solvents, such as methylene chloride – also a carcinogen – eventually replaced benzene and became integral to what became known as the European Method of decaffeination.

Organisations such as the Clean Label Project recently petitioned the California Assembly and the US Food and Drug Administration (FDA) to prohibit use of the substance, which has already been banned by the United States Environmental Protection Agency in products like paint strippers. The National Coffee Association has pushed back, arguing that all of the samples tested by the Clean Label Project were within the FDA’s level of concern.

A process for removing caffeine from coffee without the use of chemicals was developed in Switzerland, in the 1930s. Swiss Water Decaffeinated Coffee has refined that method into a proprietary process in which green coffee is immersed in green coffee extract, during which 99.9 per cent of the caffeine is released and filtered out. In the US, removal of 97 per cent of the caffeine is enough for a coffee to qualify as decaffeinated; in the European Union, 99.9 per cent must be removed.

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While it is generally considered to preserve the taste of coffee better than other methods, the method is relatively expensive. It adds US$1 to US$2 per pound to the cost of the green coffee, says Paronto – not to mention travel and time to the process, because decaffeination takes place at Swiss Water’s facility in British Columbia, Canada.

In either case, the beans are steamed to open their pores and then soaked in a solution containing ethyl acetate, which bonds to caffeine molecules before being flushed.

The coffee Zhang used was decaffeinated via a modified version in which the pulp, or mucilage, of the coffee berry is added to the fermented sugar cane solution.

“It’s a groundbreaking way to do the decaffeination,” he says, because “it not only does not take out any flavours, it imparts nuanced complexity into the cup”.

On April 12, Zhang tried his hand in the World Coffee Championships at the Specialty Coffee Expo in Chicago. Although he did not make it to the final, things are changing quickly. He thought he had a six-month supply of Los Nogales decaf, but it sold out within a week of his victory at the US Brewers Cup. The next batch, a Castillo variety, is slated to arrive at the end of April.