Jess Alper lets out a belly laugh.

She’s watching an episode of “Curb Your Enthusiasm,” and star Larry David just finds out that he was adopted and that his birth parents are not Jewish. The revelation temporarily transforms David’s character from a nebbish, 50-something New Yorker into the kind of all-American guy who fixes cars, says grace before dinner and wears sweater vests.

Rabbi Joshua Strulowitz played the clip as a catalyst for conversation at the third annual Young Adult Feast of Jewish Learning, which was held March 30 at the JCC of San Francisco.

“The first time I saw this episode,” Strulowitz said, “I wondered: Do non-Jews get the humor? That most Jews don’t hunt, can’t fix cars and have a tendency to be neurotic?

“And it got me thinking: There are certain Jewish characteristics, but what is Jewish? What makes something Jewish?”

Alper, 25, got the humor — and also nodded appreciatively when the topic was framed by Strulowitz, rabbi at Congregation Adath Israel in San Francisco.

It’s a question she has pondered a lot lately, and the reason she chose to attend this particular workshop, titled “What Larry David Taught Us: Is Being Jewish in Our DNA?”

The daughter of a Jewish father and non-Jewish mother, Alper frequently wrestles with what defines a Jew and what makes her Jewish.

“People born with two Jewish parents probably think about this a lot less than I do,” the San Francisco resident said. “But maybe there’s something valuable about having to choose my Jewish identity.”

This was the first time Alper attended the Feast event, sponsored by the S.F.-based Bureau of Jewish Education. The evening drew 430 participants, according to organizers, ranging from affiliated to unaffiliated, secular to Orthodox.

Alper looked hip in a sweater dress, tights and knee-high boots. She grew up going to both a synagogue and a Unitarian church, and for the past six months — since she began teaching at Midrasha, a Jewish high school program in the East Bay — Alper has thought more seriously about her identity, observance and affiliation.

“I haven’t yet sorted it all out in my mind,” she said.

Nonetheless, Alper — like the other young adults — was eager and curious throughout the evening.

During a workshop titled “Love in the Fast Lane,” Alper’s question about niddah, Jewish laws of family purity, sparked a lengthy Q&A session between the Modern Orthodox rabbi leading the class and the 40 or so people in the room.

The Feast included 22 workshops; each participant could select two to attend. Topics included yoga, science, politics, kabbalah, Israel, Yiddish, social justice, literature, food, history and spirituality.

In between sessions, local band Kol Creation played music reflecting the members’ Israeli, Brazilian and Jamaican roots while participants sat cross-legged, on the floor near the stage, eating a dinner of wraps and sandwiches.

Alper noshed while talking to someone she met during the “Larry David” workshop. Then, after her second workshop, she talked with two women whom she had never met before, sharing personal thoughts about relationships, dating and marriage. A passerby would have assumed they were old friends.

Mariana Roytman Schiffner, who coordinated the Feast for the BJE, said she loves hearing about people’s first time attending the event.

For example, one person approached Strulowitz after a workshop and told the rabbi he had no Jewish friends and didn’t participate in any Jewish organizations or events. He came to the Feast, he said, because he didn’t know how to connect to his Judaism, or how he would pass it on to his children once he did make a connection.

“And the rabbi said, ‘I think you just started your journey here at the Feast. I can’t think of a better place to start it,'” Roytman Schiffner said.

“When he told me this, I was just choking up — because that’s the whole point. This is a doorway to engagement, to connect us in a deeper way to who we are, where we come from and where we’re going.”