Nothing makes me feel square like being in San Francisco. It’s not just the bathrooms marked “self-identified men.” It’s not just being waved at by a convoy of naked bicyclists. It’s not just attending a neo-Orthodox Minyan that meets in a room named for the radical African-American feminist Audre Lord and for Kiddush serves cholent, quinoa and gluten-free pasta. It’s the realization that cities like San Francisco represent a frontier in Jewish history, where long-held assumptions about Jewish identity are dying and something unsettling and fascinating is being born.

Of America’s hundred-largest metropolitan areas, the Bay Area (defined by the pollsters at Gallup as the territory between San Francisco, Oakland and Fremont) is the most secular. And its Jews are even more secular than that. In 2011, a community survey asked self-identified Jews in the East Bay (which includes Oakland and Berkeley) “what is your religion?” Twenty-three percent said they had none. Another 18 percent said their religion was some form of Christianity. Less than half answered “Judaism.” A 2004 study found that a plurality of Bay Area Jewish children were being raised by interfaith parents. (The percentage has almost certainly grown since then). A comparison of 54 American cities found that the Jews of San Francisco and the East Bay were among the least likely to belong to synagogues.

Yet despite this, I could barely find a seat last Friday night at the Kitchen, a four-year-old minyan that meets in rented spaces across the city. (Full disclosure: I’ve spoken twice at the Kitchen, among many other synagogues, and received an honorarium). The Kitchen regularly attracts 150 people for Shabbat services. Seven hundred showed up last year for Kol Nidrei. And according to Rabbi Noa Kushner, 90 percent of the congregants are in their forties or younger.

The Kitchen is one of a number of newly created “synagogues” (many don’t have buildings) — IKAR in Los Angeles, Kavana in Seattle — that while not exactly the same, are succeeding for some of the same reasons.

First, they’re inclusive without being "lite." Kushner estimates that 40 percent of the Kitchen’s congregants are not Jewish. But that’s not the most remarkable part. The most remarkable part is that these non-Jews — often alongside their highly assimilated Jewish partners — attend a service where the prayers are entirely in Hebrew led by a rabbi who talks relentlessly about Jewish texts. Last Friday, faced with Parshat Shemini, a Torah Portion many rabbis would skip as too inaccessible and disturbing, Kushner dove into rabbinic explanations for the death of Aaron’s sons, Nadav and Avihu, before discarding them all and talking about the mystery of grief.

Yes, the Kitchen is welcoming. To avoid alienating her gentile congregants, Kushner doesn’t speak about “being Jewish.” She speaks about “doing Jewish.” But she actually expects people to do it. “You could be a direct descendant of Moses, but if you aren’t interested in trying anything Jewish the ride is pretty much over,” declares the Kitchen’s website. “By the same token, you can be Santa Claus himself, and if you decide to jump on the Jewish train, and are open to seeing where it takes you, then the ride has just begun.”

Communities like the Kitchen flip Jewish identity on its head. In many traditional American synagogues, the boundaries between Jews and non-Jews are clear, but the content of Jewish life is low. Today, however, especially in places like San Francisco, racial, ethnic, religious and even gender boundaries are blurring. Outside the Orthodox community, many young American Jews have little tolerance for the tribal distinctions their parents and grandparents took for granted. Many do, however, hunger for community and authenticity, for something that isn’t boiled down to its lowest common cultural denominator, and which helps them live a purposeful life. That’s what Chabad offers. And in a very different way, it’s what the Kitchen offers too.

The other reason places like the Kitchen are succeeding is that they’re not built on victimhood and fear. When they talk about Israel and anti-Semitism, many American rabbis send the message that for Jews, the world remains a perilous place. For some Jews, at some moments, it clearly is. But most young American Jews don’t feel threatened. As a mostly white, largely upper middle class population that’s been in the United States for a century, they’re more likely to feel privileged. Communities like the Kitchen make that privilege a challenge: asking young American Jews to honor the history of Jewish oppression by fighting the oppression of others. The Kitchen calls its kids program the “Freedom School,” a phrase that evokes the schools established by civil rights activists in Mississippi in the 1960s, “because we believe learning Torah will move students to justice.” On its website, L.A.’s IKAR declares that “our expectation is that every member of IKAR participates in the work of tikkun – healing” by fighting poverty, gun violence and environmental degradation.

Kushner, like her IKAR colleague, Sharon Brous, is also more willing than most American rabbis to challenge Israeli policy. I don’t think that’s what brings people in the door. But it’s connected to what does. Synagogues, like other institutions, need visionary leaders. And those leaders can’t be visionary if they check their consciences on the way to work. More important than the fact that Kushner and Brous lean left on Israel is that they speak about Israel in a way that is true to themselves. Unlike so many American rabbis, who muffle their voices for fear of offending donors, Kushner and Brous have created an environment that lets them be honest. They’re more able to create an authentic experience for their congregants because they are being authentic themselves.

In an American-Jewish community that is reaping the consequences of generations of religious illiteracy and indifference, rabbis like Noa Kushner offer some small measure of hope. Yet the Kitchen receives a mere $25,000 a year from the Jewish Community Federation of San Francisco, which gives Israel-related groups more than $4 million. If you want to know why the American Jewish establishment is failing to nurture joy in, knowledge of, and fascination with Judaism in the next generation of American Jews, start right there.