Last month, writer and journalist David Sax visited the Sixth & I Historic Synagogue in Washington, D.C., to kibitz about a favorite, salivating subject: the delicatessen. Sax's findings and dispatches on the cured meat business, and what it has meant for changing contemporary Jewish identity, are collected in his first book, "Save the Deli: In Search of Perfect Pastrami, Crusty Rye, and the Heart of the Jewish Delicatessen."

A Toronto native now living in Brooklyn, Sax's travels have taken him to delis around North America and across the Atlantic, from Detroit to Los Angeles, Montreal to Brussels. With true immersive journalism zeal, he even landed a one-night gig slicing meats at the legendary Katz's Deli in Manhattan's Lower East Side. He likened the experience to "a minor league ball player being called up to pitch in the bigs."

Amid his more amusing anecdotes -- such as how his belt size actually remained intact over the course of his research, despite making up to six trips to different delis every day for three months -- Sax also drives at the more serious issues facing delis in the 21st century. Tracing the downfall of the authentic, ethnic deli, he holds out little hope for its comeback, blaming cultural assimilation and shifting values over the last several decades.

Sax explains that with the great influx of Eastern European Jewish immigrants to North America at the turn of the 20th century, people set up delis to honor and serve traditional cuisine, with the expectation that new immigrants would continue to flock to America, hungry for their favorite dishes. But after the devastation of the Holocaust, with whole generations wiped out, the purveyors of the original, ethnic fare did not continue to immigrate. With every subsequent, further Americanized generation, the connection to the tradition becomes weaker.

"People have come to fear the foods our parents and grandparents have grown up with," Sax told the audience at the synagogue. "The idea, fifty, sixty more years ago, that you would have fatty meat, this was the greatest pleasure you could have. And now people go to the deli and they say, 'I want the corned beef lean, I don't want a speck of fat on it.' And then they get the sandwich and they say, 'I don't understand why it's dry?'...This is terrible!"

Indeed, the terrible truth is even direr: Endangered by health trends and the economic challenges facing family-run businesses (like the increasing aspirations of immigrant parents for their children), explains Sax, classic delis are in shorter and shorter supply.

"With assimilation," he said, "the first thing to go is generally language," and then religion, and finally, food. And thus, the title of his book, "Save the Deli," is more than a plea to preserve pastrami on rye, but really a plea to preserve a cultural link to the past.

Luckily that night, the cookies and knishes served to the crowd in the synagogue basement were not in short supply, as the author and audience gathered afterward to eat, meet and schmooze.

[Watch a video of the event as the Washington Post's Ezra Klein interviews David Sax on the Jewish deli and diaspora cuisine.]

Untitled from ryder Haske on Vimeo.