In June 1968, famed graphic designer Milton Glaser co-authored “A Gentile’s Guide to Jewish Food” for New York magazine, introducing non-Jews to myriad smoked, pickled, and salted fish. Photos of the display cases at the iconic New York appetizing store Russ & Daughters helped the novice along.Reading Glaser’s article 52 years later, I particularly wanted to taste kapchunkas, strings of whole dried whitefish with their guts still inside, which used to hang from hooks and drip their fat onto Russ & Daughters’ then sawdust-covered floor. Kapchunkas “look somewhat ominous but are worth trying,” Glaser wrote, promising, “a robust flavor, a taste more favored in Europe.”So I visited Russ & Daughters, where the vintage seltzer bottles and hand-stenciled signs for smoked eel and kapchunkas helped me imagine my immigrant grandmother coming here when the shop opened in 1914. If she did, my great-grandfather Welwel would have given an order in Yiddish for schmaltz herring, guts in and head on, to fry up at home. It would have been a cheap source of protein and comfort food for a buttonhole maker, his wife, and six daughters. A little different from today’s $15 Super Heebster bagel sandwich with wasabi roe or a sit-down brunch at Russ & Daughters’ café.The cover of that issue of New York still hangs on the wall of Russ & Daughters—but a third of Glaser’s recommendations have disappeared from the displays. Lox, which Glaser called “King” of Jewish cured fish, and sturgeon, which he crowned “Emperor,” still reign. But the mere peasant fish (pickled sprats, salmon trout, winter carp, sandalwood matje herring) have been banished from the kingdom. And so have kapchunkas. Only the old sign remains.Appetizing, which Russ & Daughters defines as “the foods one eats with bagels,” has always negotiated between the old and the new. In the early 20th century, Jewish immigrants on the Lower East Side started the appetizing tradition, as they reshaped shtetl customs to fit cosmopolitan New York. Russ & Daughters’ founder, Joel Russ, who lost his peyes when he came over, split the difference between the traditional and modern. He opened a kosher-style store—not mixing meat and dairy but breaking with Orthodoxy with Saturday noshes of nonkosher sturgeon. These days, his great-grandchildren bend tradition to fit a city that longs for authenticity but finds bloody marys more appetizing than kapchunka. “We’re enabling you to connect with your great-grandfather,” the fourth-generation owner, Niki Russ Federman, told me, “but you’re also having a very modern contemporary moment.”Glaser, who passed away in June at the age of 91, profiled “appetizing” at the halfway point between my great-grandfather’s generation and mine. The lead illustration of “A Gentile’s Guide to Jewish Food” is of a squeamish fish stuck in a bagel. The Forward called it “a light, playful jab at a city that loved to tout its Jewish heritage, and could be simultaneously skittish about that heritage’s more messy details.” Glaser aimed to put New Yorkers at ease with appetizing stores, which with their pickled vegetables, whole fish wrapped in newspaper, dried fruit, and strings of mushrooms, seemed impenetrable to gentiles.The guide was co-written with Jerome Snyder, the same year Glaser co-founded New York magazine. The previous year, Glaser had won acclaim for his Bob Dylan poster, which defined the 1960s aesthetic. Then, in 1977, his I♥NY logo became part of the city’s identity. Glaser’s fame as a graphic designer overshadows his legacy as a magazine man and food writer, but his and Snyder’s column, “The Underground Gourmet,” was groundbreaking. Predating foodie blogs by decades, they sniffed out affordable, off-the-radar ethnic restaurants, introducing readers to “mysterious New York specialties,” which according to them included “Puerto Rican cuchifritos, Jewish knishes, and Chinese dim sum.” Today, some find the terms “cheap eats” and “ethnic food” degrading. However, Glaser and Snyder were genuinely trying to elevate food mostly ignored outside of ethnic enclaves—including their own cuisine, Jewish food.Since then, much of Jewish food has become “New York food,” like pizza or hot dogs. Bagels, albeit softball size, toasted, and stuffed as if they were ordinary goyishe bread, are found everywhere. A few appetizing stores survive by offering the quality and authenticity you can’t find in a rainbow bagel. Murray’s Sturgeon Shop has barely changed since it appeared in Glaser’s guide. “This store was built this way in 1946,” owner Ira Goller boasted to me. His mainly older and Jewish clientele value the consistency. “They come for comfort,” Goller said.Even Russ & Daughters, with a younger and mixed Jewish and gentile clientele, keeps the flavors consistent. They may have expanded to online nationwide shipping and two restaurants, but “the goal,” Russ Federman said while standing under a portrait of her great-grandfather, is “to connect people with taste memory and identity.”If taste memory sells, then where are the fish Glaser considered Jewish staples? Chubs (small fat whitefish) like butterfish have become unfishable, victims of the Great Lakes’ changing ecology. They’re seldom found and sorely missed. Other products just stopped selling. At Russ & Daughters, gone are the “stacks of shimmering golden skinned whitefish” that Glaser called “the most dramatic feature of any appetizing store counter.” Now a few lonely fish stare up hopelessly at customers who prefer ready-to-eat bagel sandwiches. Gary Brownstein, whose grandfather founded Acme Smoked Fish Company in 1906, told me that things changed when cured fish became more mainstream in the 1980s: “People stopped eating fish with bone in it.”Brownstein and Goller aren’t sentimental for the more pungent fish that got away. Russ Federman explained, “Today, people’s palates don’t appreciate salt so much.” Goller, who is 63 years old, agreed: “These are foods my grandparents ate,” and he doesn’t miss them. “My generation grew up not liking the smell of kippers,” he said.But taste memory doesn’t have to taste good. We eat maror at the Seder table to remember the bitter times of ancient Egypt. Why not eat kapchunka to remember the shtetl? One reason is that kapchunka is uneviscerated, salted, and dried without refrigeration. In 1985, an elderly couple in Queens died of botulism from improperly prepared kapchunka. “The FDA came in and said no more kapchunkas,” recounted Russ Federman, “and my father told me that he was actually happy ... It was so intense.”I was intrigued. I wear my love of gefilte fish as a badge of honor, so I felt ready for kapchunka.I sought it out in a Jewish community deeply committed to tradition even in the face of health risks and government regulation. In Hasidic Borough Park, at Schwartz Appetizing, unlike at Manhattan spots, herring—which Glaser called “the most proletarian of all the fish”— dominates. Still, even in this insular community, I could see the recent influence of Mexicans from nearby Sunset Park: The store sells jalapeño pickled herring. Brooklyn’s Hasidic community may resist modern garb but not modern fish preparation. Borough Park is swimming with kosher sushi but, alas, no kapchunka.It’s not surprising that even in the most traditional circles, appetizing draws on the New York melting pot. Glaser wrote in his guide, “The Jews exercise an international gastronomic curatorship by bringing together and developing foods of Scandinavian, Middle European, and Near Eastern origins.” He could have added the Lower East Side, where Jews first embraced lox and then in the 1930s sandwiched it in a bagel with a schmear. What is now a classic is relatively modern, according to Gil Marks’ Encyclopedia of Jewish Food.Peter Shelsky is looking for the next frontier. In 2011, he left a fine dining career to open Shelsky’s of Brooklyn in Cobble Hill. “I wanted to bring appetizing back to its glory and try to find new products,” he said. His bestsellers are the classics, but he has innovations like a wild king salmon bacon, and an egg bagel seasoned with Himalayan black sulfur salt, turmeric, and annatto. Risky business in a city that shames politicians for even the mildest offense of toasting a bagel. Nonetheless, Shelsky’s mostly Jewish clientele praise his Sichuan peppercorn bagel, and The New York Times extolled his pork roll, egg, and cheese on a bialy.Brownstein, likewise, who started at Acme over 45 years ago, experiments with new flavors. He was inspired by the diversity of customers who started buying traditional Jewish fish products. Since 2002, each Friday Brownstein creates “Gary’s Special.” One recent week it was a smoked salmon poke with mango, tomatoes, and jalapeños. For Brownstein this isn’t Jewish food, it’s New York food. However, diaspora Jews have long adapted to and borrowed from the world around them, while remaining Jewish. Why can’t our food include mango or Sichuan peppers in 2020 Brooklyn?But I still wanted kapchunka. I wanted to know the Eastern European roots of appetizing before I dug into its future. So, I went to Brighton Beach, to find older Russian-born Jews unblemished by jalapeños and the brunching habits of millennials. Piles of Glaser’s “shimmering golden skinned” bone-in fish live on. His salmon trout survives, under the name segma. I even heard rumors of kapchunka. The closest I found was a whole, salted, air-dried whitefish—the only catch being that it was eviscerated. So, not true kapchunka, but legal, and close enough.I finally got to taste it.I wasn’t sure if the “no guts, no glory” rule holds here, but after one bite of kapchunka, I’d had enough. It was chewy, incredibly salty, and as Glaser politely put it, “robust”—but in a way that makes you unsurprised that it’s killed people.I headed back to the F train and thought about stopping at Shelsky’s of Brooklyn or Russ & Daughters. Appetizing has a rich history, but also an exciting future. I now crave Sichuan peppers or wasabi roe on my bagel. Just don’t toast it.