Getting millennials into a synagogue isn’t easy, Jewish professionals often say. It’s an issue that vexes lay leaders and clergy alike.

Some say those born from the early 1980s through the mid-to-late 1990s are too transient, or too distrustful of large institutions. Some say stodgy synagogue experiences growing up turned them off for good.

But at Congregation Emanu-El, established in 1850, clergy and lay leaders believe they’ve found the formula over the last 20 years — and it’s about more than replacing “Manischewitz and cookies,” they say, with “tacos and beer.” (Though that certainly helps.)

“We meet people where they are,” said Rabbi Sydney Mintz, one of the originators, along with Cantor Marsha Attie, of the monthly Late Shabbat — the “centerpiece” of Emanu-El’s young adult programming, which also includes things like hikes, tree planting, meditation groups and mountain biking.

On Nov. 8, Emanu-El celebrated the 20^th anniversary of Late Shabbat. What began in 1999 with about two dozen people has transformed into an “institution,” said Alan Greinetz, president of the synagogue’s board of directors.

Held after the synagogue’s main Friday evening service, the 8:30 p.m. “late” service draws hundreds of 20- and 30-something each month. It’s calling cards are music, spirituality, swaying and clapping, lighthearted jokes and affecting melodies from a full band — and, what is for some the main draw, a post-service oneg with bourbon, craft beer, wine and tacos, all for free.

“If you’re not attracting young people, you’ve got a sustainability problem,” Greinetz said. “It’s just an incredibly warm, inviting way for people to get back in touch with Judaism and meet other young Jewish people in the city.”

As a partial byproduct of Late Shabbat, Greinetz added, “We’ve got more young members than most congregations.”

Mintz estimated the number of “young-adult households” at Emanu-El at close to 700 — “the size of many congregations,” she pointed out. Overall, Emanu-El’s membership consists of approximately 2,100 households.

Late Shabbat is usually held in the smaller Martin Meyer Sanctuary the second Friday of each month, but the anniversary gathering saw hundreds fill the massive main sanctuary, with some traveling in from out of town.

Among the attendees was Gregory, a 33-year-old coder originally from Russia, attending Late Shabbat for the first time. And Marni, a 21-year-old Santa Clara University student, who said she finds Late Shabbat “energizing” and “uplifting” and, of course, “an opportunity to meet new people.”

Mintz, Attie and Rabbi Jason Rodich (Emanu-El’s designated millennial rabbi) led the service, which emphasized community. The rabbis dimmed the lights before the Amidah to encourage introspection; during the Hashkiveinu prayer, congregants linked arms with those next to them to form a Sukkat Shalom, a shelter of peace. “It’s a nice way to relax after a long week,” said Misha, an attendee in his thirties.

The clergy was backed by two acoustic guitars, bass, mandolin, flute, hand drums and chimes. They played recognizable prayer melodies plus songs by Matisyahu and Bob Dylan. To celebrate the anniversary, Rodich poured tequila shots from a flask that emerged from his pocket.

There were moments of poignant reflection, too. Rodich read from the poem “The Summer Day” by Mary Oliver in the middle of the Aleinu prayer. “Tell me,” he said, with soft strumming backing him. “What is it you plan to do with your one wild and precious life?”

Afterward, everyone spilled out into the foyer and the chilly courtyard for dinner, drinks and shmoozing.

Twenty-seven-year-old Sam and 25-year-old Aaron chatted near the craft beer and wine table. Aaron, who works for a software company, said when he agreed to come to Late Shabbat he didn’t even know there was a Shabbat service involved. “I thought it was just drinking and shmoozing,” he said. Still, he called the service “beautiful.”

Dan ate tacos while waiting for a friend to finish a conversation. A Facebook employee in his early 30s, he said he doesn’t come to synagogue often. But he believes feeling part of a community, or “tribe,” is “vital to human flourishing.”

Danielle, a 25-year-old Catholic, said she looks forward to Late Shabbat every month. She attends the service with her Jewish boyfriend and other friends. “You get to meet a lot of interesting people. No one cares that I’m a different religion,” she said. “It feels very — nonjudgmental.”

The social element of Late Shabbat was universally acknowledged, as was the possibility one might find a romantic connection. This night had even more intriguing possibilities, as after the oneg, many of the attendees took Ubers to Ireland’s 32, a sports bar in the Richmond District, for a raucous after-party hosted by noted millennial Jewish party planner Adam Swig.

“I can’t even tell you how many weddings, and how many children were born, as a result of Late Shabbat,” Mintz said. “I’m doing a bar mitzvah of a kid this year whose parents met at Late Shabbat.”

Still, Mintz said Late Shabbat began simply because “there were few spaces in the city for young adults to engage in Judaism.” And many Jewish spaces had a barrier to entry — “a price tag attached to Jewish identity,” she said.

“Shabbat is this 4,000-year-old tradition that has kept us going, kept us alive, and kept us centered,” she said. “In 2019, we need it more than ever.”