Ralf Ruller wanted a sacred ground for coffee connoisseurs in the heart of Berlin, somewhere devotees could sip their drinks free from distraction.
This purist - not to say militant - approach to coffee drinking extended to a long list of rules at his brew bar, the Barn Roastery, including a ban on extra milk, spoons, laptops, dogs, mobile phone ringtones, and loud phone calls. Sugar is strongly discouraged. But the rule that has provoked the most heated reaction is Ruller's decision to prohibit pushchairs and prams.
"Coffee Nazis, choke on this swill" and "totalitarian coffee regime" are just two of the many messages of protest Ruller received after he installed a stone bollard - complete with a picture of a pram with a red line through it - in the doorway of his coffeehouse in the northern Berlin district of Prenzlauer Berg. (The bollard is moved for wheelchairs.)
Marianne Burket-Eulitz, a family policy expert for the Green party, called Ruller's attempts to keep prams out "a socially incorrect affront to families".
But the former actor turned barista is unapologetic, upset only that his brews - which are prepared with delicacy and attention worthy of a Japanese tea ceremony - are not receiving the attention he believes they deserve.
"People should listen to their senses when they drink a cup of coffee. Just as we take care of the coffee bean from crop to cup, we also take care of the people who come in here to drink it," he argues, pointing to customers chatting, reading newspapers or gazing at the goings-on on the Schonhauser Allee.
Ruller's young team demonstrate the brewing process to customers, measuring temperatures and weights, checking aromas, "taming" froth, and timing to a second the silky brown creations distilled out of vacuum presses and siphons.
The staff, who come from as far afield as Australia and Mexico, include Rob MacDonald, a dairy farmer from Australia who claims his taste buds are so refined he can tell what a cow has eaten from the flavour of its milk. "I love this artistic approach to coffee," says the 27-year-old, who as well as training to be a barista is - perhaps inevitably - learning to play the jazz xylophone.
Ruller's buggy ban comes amid a bitter turf war between two groups of locals. Prenzlauer Berg is known for its high concentration of young families but over the past few years, tensions have mounted between these younger incomers and older, often poorer, long-term residents - many of whom feel squeezed out of the now gentrified district, which once lay ignored and crumbling in the communist east of the city.
He is the first to call himself a geek, and takes comfort from the fact that support for his coffee shrine has been just as strong as the opposition. "Good move, dude! You're setting an example that hopefully will be followed by many before long. Moreover, I've never met a toddler who liked coffee anyway," wrote one fan on The Barn's Facebook page.
Some young mothers have also expressed their appreciation at his pushchair ban. "There's space enough here to fit in 20 prams," says Anne Rech, 36, a sales manager watching her cup of washed El-Salvador Kilimanjaro being carefully prepared while, strapped to her in a carrier, her nine-month-old daughter, Philippa, gurgles quietly. "But why should they? There are plenty of dedicated child cafes people can go to if they want their kids to run around."
Before moving back to Berlin several years ago, Ruller worked as an actor in London, where he often played Nazi soldiers in British TV war dramas. He says it feels as if he has been cast as the Nazi in his own coffeehouse drama.
Though initially hurt by attempts on Twitter to label him the "Soup Nazi"- a reference to the infamous soup-stand owner in the US sitcom Seinfeld who demands his patrons abide by a strict set of rules - he laughs as the comparison is not so far off the mark. "Like him, I'm incredibly proud of my product and want people to respect it," he says.