Roger Horowitz’s Kosher USA is one of those terrific books that reminds us how little we know about the world. Before reading it, I had always operated under the (embarrassing) assumption that all it took to be kosher was eating food blessed by rabbis and keeping separate plates for meat and milk. Little did I know about the intricate debates Jews have been having for two thousand years about, for example, whether a sturgeon’s tough appendages satisfy the biblical kosher requirement of “scales.” More importantly, I did not know that kosher food was big business, and that it evolved—but did not always grow—in close connection with the development of America’s modern industrial food system.

Horowitz offers two seemingly divergent yet ultimately symbiotic storylines. The first, in line with prevailing popular narratives of these events in the United States, is a story of success; over the course of the twentieth century, the availability and profitability of kosher packaged foods exploded. The second narrative, chronicling the rise and fall of large-scale kosher meat production in the United States, strikes “a more troubling tone” (4) and offers a “fuller, more complex, and at times more disturbing history” (5).

Cleavages were always present—among Orthodox, Conservative, and Reform Jews’ competing definitions of kosher (as well as between competing interpretations traceable to Ashkenazi or Sephardic traditions) and between lay science and rabbis—but powerful forces buttressed the rise of Kosher USA. Above all, kosher law gradually integrated modern food science. An early chapter details how (some) Coca-Cola became kosher. Horowitz writes that “it was the dynamic engagement of rabbinic authorities and food companies that yielded kosher Coke and opened the door to the widespread expansion of kosher food in America” (20). Coca-Cola was not kosher because, like many food products, it contained glycerin, a by-product of making soap from animals—usually treif, or non-kosher, animals. Coke offered a special version of its soda for Passover with a cottonseed oil–based glycerin, but this did not resolve the matter. Not until the late 1950s, when the company and Procter & Gamble invested thousands in a separate production line to ensure that even traces of meat-based glycerin did not come into contact with plant-based glycerin, would most Jews accept this special-run Coke as kosher. The Coke story shows that, by the postwar years, the science-based kosher certification vision of an Orthodox rabbi and chemist from New York named Abraham Goldstein had prevailed. Goldstein launched what eventually became the Orthodox Union certification agency.

The rise of “industrial kosher” in postwar America deepened the divide between Orthodox and Conservative Jews. Jell-O was an important fault line. Orthodox Jews deemed all gelatin derived from non-kosher animals as treif, whereas Conservatives, building on an ancient exception that allowed kosher honey to contain trace amounts of otherwise non-kosher bees’ legs, insisted that the process of making gelatin produced a completely new and thus kosher material. Jell-O’s manufacturer, General Foods, claimed the product was kosher, but most kosher consumers followed the Orthodox certifiers. The Orthodox Union became the dominant player in an oligopolistic industry of certifiers acting as a sort of trade organization; together, the certifying agencies erected an impressive system that sent certifying rabbis throughout America’s food system and greatly expanded the number of kosher products. Early in the century, many homemakers relied on themselves to determine what was kosher; after World War II, third-party expertise prevailed.

Several factors beyond Jewish organization and lobbying promoted the proliferation of kosher offerings. Increasing food regulation demanded detailed analysis and testing of ingredients, the kind of science that made certification easier. Kosher often prevailed, because the investments it required were relatively modest. Indeed, beyond the goodwill they earned from appealing to a small minority of observant Jews, many companies profited from making basic ingredients such as vinegar, oils, and syrups kosher, because industrialized food contains so many ingredients that kosher ingredients made life easier for firms downstream. Additionally, in an era before organic food was widely available, many gentiles who valued pure food bought kosher, as did many Muslims, and so did institutions such as prisons that found it cheaper to provide some kosher food always rather than make special arrangements for some. Sometimes the success of kosher simply relied on quirks of demand. The wildly entertaining chapter on sweet kosher Manischewitz wine reveals how many African Americans in the middle of the twentieth century consumed this wine because it reminded them of the wine their Southern grandmothers used to make with scuppernong grapes. Because of all these factors, observant Jews never approached the majority of consumers of kosher food.

Horowitz’s summary of the difficulty in producing decent and affordable dry kosher wines—like every section, filled with just enough detail to explain the nuances of kosher law and debates—serves as a bridge to the second, less-happy narrative of the decline of kosher meat in the United States. Just after World War II, several kosher slaughtering facilities closed in New York to make room for the new UN building. For a time, an entrepreneur named Harry Kassel filled the void by effectively combining modern industrial meat production with schechita, the Jewish system of kosher slaughter. His secret was combining kosher and non-kosher streams under the same roof; while his cattle forequarters could only enter the kosher market, his hindquarters enjoyed success in the general beef market. By the 1970s, however, Kassel’s firm and the larger American kosher meat industry were in crisis. Schechita slaughter necessitates elevating an animal’s rear leg while restraining its head. New technology tried to make the practice more humane, and federal slaughtering regulations carved out exemptions for religious practices, but animal rights activists (occasionally backed by anti-Semitic–driven complaints) dented the appeal of kosher meat. More significant was the broader consolidation of the meat industry into just a few major players, which made it even harder for small firms to compete. By the twenty-first century, kosher meat was a niche product. A few years ago, Agriprocessors, something of a spin-off from Kassel’s defunct firm, declared bankruptcy after years of attack from People for the Ethical Treatment of Animals and repeated violations for using undocumented-immigrant labor.

The two narratives in Kosher USA diverge but are not contradictory. Kosher meat became marginal, whereas all Oreos became kosher in the 1990s, because only the latter made economic sense. “By the twenty-first century,” Horowitz writes, “kosher food was embedded in an industrial food system structured by rules and practices developed outside Jewish law and with the principal intent of satisfying a non-Jewish market” (254). Which is not to deny the importance of this story to broader currents in Jewish American history. In part through just the right amount of humorous first-person family stories, Horowitz convincingly argues that kosher food—and arguing over what constitutes it—“affirmed Jewish traditions . . . [and] confirmed[ed] our greater membership in what it meant to be Jewish” (17). Moreover, the rise of Kosher USA contributed significantly to the continued vigor of Orthodox Judaism in the United States. In the 1980–81 fiscal year, Orthodox Union “revenues comprised 75 percent of the total income for the parent Union of Orthodox Jewish Congregations” (102).

In the epilogue, Horowitz highlights a central conundrum of American Judaism. It has generally embraced modernity, but, when subsets of it rely on twelfth-century theology and food science or insist that kosher slaughtering can be divorced from concerns about the ethical treatment of animals (and workers), it has tried to keep modernity at bay. In the end, perhaps kosher food’s ambiguous relationship to modernity is what makes it quintessentially American.