ZURICH — With his converse sneakers, faded jeans, sweatshirt and blond curls, Rolf Hiltl doesn't look like a sandals-and-socks missionary determined to convert Switzerland to vegetarianism. The 51-year-old heir to the restaurant bearing his name is an easy-going type who does occasionally eat meat, describing himself as a "flexitarian."

People in Zurich find it "quaint" that his restaurant will soon have served up food for 120 years without a single animal being killed. "If we had served meat in this time, imagine all the corpses that would have piled up by now, much bigger than this house," says Hiltl. His family's story reflects the history of vegetarianism here in the heart of Europe, from a priestly vocation to fashionable, to its current status as, well, normal.

Ironically, though, Zurich has not embraced this mainstreaming: This Swiss city where in 1898 the Hiltl became the world's first exclusively vegetarian eatery, counts relatively few restaurants today serving no meat.

Still, the Hiltl family company continues to grow, now including six restaurants, a cooking school, a grocery with a meatless butcher's shop and a night club, all drawing in between 3,000 and 5,000 customers a day. Hiltl will not give more figures, as this is a "family firm." A new, seventh restaurant is set to open in the fall of 2017 in downtown Zurich, on the lively Langstrasse street, and like the flagship restaurant, will have a basement club. Rolf Hiltl partnered up with the Frei brothers in 2000 to launch the other chain of vegetarian self-service eateries Tibits, now with nine premises and employing 400 people.

The restaurateur's decision to expand into the night club world was strategic: to rid his establishment of the whole "seed-eating" image, and replace it with the aura of partying, wild fun and nocturnal hedonism that appeals to younger clients. "Our DJs go from hip hop to R&B, they have tattoos on their arms and don't eat meat like many other young people of their generation. But there's vodka, and that's not meat," he says.

The next revolution

The owner, who himself prefers to spend an evening at home cooking for the family or skiing in Zermatt, is a real believer in the power of diversity: proud to be employing 250 people from 60 countries and using as many Swiss or European ingredients as possible. He is very active on social networks, and every tweet with the #Hiltl hashtag is projected in real time onto the wall in one of his restaurants.

Rolf Hiltl learned his own cooking craft in Zurich at the Grand Hotel Dolder, where he was trained to make the classics of French cuisine. Today, he promotes their vegetarian version: Whether à la tartare, sliced, or filleted and sauced, the dish will come with the tofu or seitan that make meat eaters howl. "As a cook, I know that what brings flavor to a dish is above all how it is prepared, and the sauce, spices and herbs. Our customers also want some tradition, and we give it to them," he says.

His great-grandfather Ambrosius, a German migrant to Zurich, decided to start the future temple of vegetarian food for health reasons. He had gout, and his doctor predicted the worst misfortunes if he did not stop eating meat. Initially, the austere Hiltl was called the "House of Vegetarians and Café of Abstinence."

In its first years, the café"s "herbivore" customers were said to enter surreptitiously through a back door. Prejudices in the food business can do great harm, and Rolf Hiltl is obsessed with eliminating as many as possible. When he took over from his father in 1998, he introduced wine and beer into the vegetarian establishment. Horror! "My grandmother and I got on very well, but she did not speak to me for three weeks," he recalls.

She was not the only one who needed convincing. The city government that issues liquor licenses initially refused the request to serve booze, insisting that a vegetarian restaurant needs no alcohol. "It has taken time for people to associate vegetarian food with pleasure. But in Zurich, we've moved onto something else. The next revolution is vegan."