Antoine Chemel, 22, opened Bar Antoine Lounge earlier this month on the mezzanine of Le Parc Bistrobar in San Francisco's Union Square, taking over the upper floor of a restaurant business his family has run since converting its two-Michelin-starred Palo Alto flagship into casual formats.

The new 80-seat bar — spread across a bar counter, leather banquettes and velvet armchairs against dark wooden walls — anchors its food menu between $9 and $38. Bar bites include escargots croquettes ($12), truffle gougères ($20), beef brochettes ($38), hazelnut-ice-cream-filled macarons ($9) and a $22 riff on Baumé's salmon mousse, served in a bamboo steamer basket under the name "Dim Saumon." The cocktail list carries over the French-leaning program Christie Chemel built for Le Parc downstairs.

The concept is a family pivot rather than a standalone launch. The Chemels had planned a renovation of the upstairs dining room this year when they decided a bar would serve the business better. "Antoine wanted to open a bar," said Bruno Chemel, Antoine's father. "And we have some customers who come to the restaurant and say, 'Oh, can we have a drink after?' We didn't know where to send them."

Antoine Chemel's operational credentials predate his legal drinking age by a decade. By middle school he was doing after-school prep work at Baumé, the Palo Alto fine dining restaurant where his father held two Michelin stars and ran a 15-course tasting menu with a mandatory wine pairing starting at $398 per person. At one point Bruno and Christie Chemel operated Baumé with no employees besides their young son. "I tried to kick him out of the kitchen, but he kept coming back," Bruno Chemel said. "They called it the two-and-a-half kitchen team, because he was the half."

Before college, Antoine rose to sous chef at the family's Le Parc Bistrobar, which opened in summer 2024 inside the Galleria Park Hotel. He left to study business and economics at De Anza College in Cupertino, uncertain about staying in restaurants, then reconsidered after rewatching a home video of himself sautéing asparagus at age 11. After "some more thought and some more eating," he returned.

The family's trajectory tracks a broader downshift from fine dining. The Chemels converted Baumé into a mom-and-pop operation in 2015 to oversee every element themselves, held its Michelin stars until 2021, then turned it into the more casual Bistronomie by Baumé — which closed the following year. Bruno Chemel, who once aspired to three stars and kept a collection of vintage red Michelin guides at the restaurant, says he spent several years asking to be removed from the guide, calling the award a "distraction."

At the new bar, Bruno helped develop the menu and coached his son through the opening weeks. Beyond that, he is handing off operations, even though Antoine has been of legal drinking age for only about a year. "He's ready," the elder Chemel said.

Father and son now work what Antoine describes as a four-handed service. "We call ourselves a great duo," he said. "We can read each other's minds at times. We don't have to say too much to know that if I'm cooking something and I'm about to plate something, he can take over the cooking."

The pattern of restaurateurs' children taking the helm young extends across the industry. In New York this month, George McNally, 23, son of Balthazar founder Keith McNally, opened his own restaurant, Faux. Shake Shack founder Danny Meyer's daughter Hallie launched Caffè Panna at 26 in 2019. Kathy Fang opened Fang in San Francisco at 27 alongside her father, Peter Fang, owner of House of Nanking.

For Antoine Chemel, the pressure is internal. "More of the pressure is just me on myself," he said — a standard he applies to Baumé-era dishes re-engineered "his way" for a bar menu priced well below the $398 tasting format that trained him.