More so than even the synagogue, the deli was the defining gathering place for the New York Jewish community for much of the 20th century. After 10 years of research, Ted Merwin has published the definitive history of the Jewish deli and all its iterations, from strictly kosher spots that close on Shabbat to the famed theater district hot spot Reuben’s that is said to have coined the eponymous sandwich – corned beef, Swiss cheese and sauerkraut on rye.Merwin’s Pastrami on Rye traces the rise and subsequent decline of the iconic Jewish deli, from its humble beginnings to its place in Broadway stardom to its quiet fade into obscurity.“Although my family did not belong to a synagogue, did not observe Jewish law, and celebrated few Jewish holidays, eating in delis offered me a sense of Jewish identity that I found in few other places,” writes Merwin.Indeed, the deli as an integral part of New York history didn’t take off until after World War I, when second-generation Jewish immigrants were experiencing a modicum of financial success and quickly shedding their religious identities. Most of the famed delis that graced the streets of New York – including the Carnegie Deli, Reuben’s, Lindy’s and The Stage Delicatessen – were not just not certified as kosher; they served meat and dairy together and some even offered bacon and pork in their sandwiches.While more humble and family-oriented delis popped up on the Lower East Side earlier in the 20th century, the theater district restaurants were glitzy and glamorous, serving both theatergoers and the show’s stars.“Its clientele imbibed the show-business atmosphere like slabs of brisket soaking up barrels of brine on their way to becoming corned beef and pastrami,” Merwin writes of The Stage Deli.As Broadway itself reached a peak, “no New York eateries were more emblematic of show-business culture than were the theater-district delicatessens, which transformed the ordinary sandwich into a fancy meal,” he added. In part, he notes, because “no ethnic group was more involved and invested in popular culture than were the Jews, who provided the lion’s share of the creative talent, financial backing, and real estate for the entertainment business.” While the image of the deli was suddenly imbued with star power, the food on the menu retained its humble nature: “The exterior of the menu represented how Jews wanted to be seen on the outside; the interior revealed how they actually felt and operated on the inside, still tied tightly to their ethnic origins.”Aside from Broadway, delis also received a boost from women entering the workforce in greater numbers, outsourcing the culinary responsibilities that once occupied the bulk of their time.Despite the upward mobility and decreasing religious observance of Jews through the 20th century, most continued to cling to the culture and heritage associated with the food. Indeed, while New York was the center of the Jewish deli trade, and communities cropped up across the US, they brought with them their deli fare. By World War II, the Jewish deli and its food – from pastrami to corned beef, liverwurst and potato pancakes – had become a national institution, an integral part of the famed New York culinary scene.Merwin recounts the amusing anecdote of a 1965 space expedition named Gemini 3. Astronaut John Young was given a corned beef sandwich from Wolfie’s Delicatessen in Florida to bring on board by a fellow astronaut. Mid-flight, Merwin says, Young whipped out his sandwich and offered a bite to fellow astronaut Virgil Grissom.“After the astonished Grissom took a bite, he noticed nervously that crumbs of rye bread were started to float around the cabin and the smell of beef was beginning to permeate the ship.” Both astronauts knew bringing the sandwich on board violated NASA rules, and were chastised for the incident.But while Jews’ upward mobility had in part fueled the deli’s heyday, as third- and fourth-generation immigrants moved out into the suburbs, they clung less and less to their culinary identities and opted instead for the more exotic and enticing fare of other ethnic groups.The deli also suffered as customers put a higher premium on healthy food and as a result of the rise of packaged and frozen foods available widely in supermarkets in the second half of the 20th century.Today, Merwin laments, the deli is an “endangered species” in New York, fallen far from its ubiquitous heyday. But he doesn’t entirely despair, as the 21st-century deli isn’t dead, it is just reinvented. While some delis add on sushi or shwarma to extend their appeal, other “artisanal delis” are found “riffing on their grandparents’ pastrami sandwiches and matzo balls,” proving that “these old dishes have had new, organic life breathed into them.”In his eminently readable book, Merwin manages to draw a timeline of American Jewish history alongside the trajectory of the deli and remain somewhat upbeat, despite its precipitous decline.While the deli will never again occupy the central role it once played in US Jewish life, members of today’s generation are playing on Jewish culinary identity in the way it best fits them.