The Kosher Conversion

The market for kosher food is growing, for reasons both practical and spiritual

Passover is when Jewish eating habits seem the most distinct from those in the rest of the world—the most restrictive, the most inexplicable. Keeping Passover means adhering to rules and traditions on top of the standard rules of kashrut, or keeping kosher, which include not eating shellfish or pork and separating anything containing milk from anything containing meat. At Passover bread and all other leavened foods are banned, and the questions of what is and isn't allowed only start there. Corn or no corn? Rice or no rice? Must staples that don't need to be marked kosher the rest of the year—milk, for instance—be marked "kosher for Passover," along with the matzoh? (As with all questions Jewish, it depends on who's answering.)

And yet Passover is the time of year when sales of kosher foods reach their peak, and when the greatest number of Jews follow some form of dietary abstention. A moment of generally happy reconnection with Jewish identity, Passover can move usually unobservant Jews to consider keeping kosher year-round. With its many preparatory kitchen-cleaning requirements, it is also the most logical time to make the switch.

The market for foods certified kosher has been steadily increasing for at least a decade. Menachem Lubinsky, a marketing consultant and the editor of Kosher Today, a trade magazine, estimates that of $500 billion in retail grocery sales last year, $185 billion was certified kosher—a rise since 1988 of about 285 percent. As of 2004 fully 85,000 products were certified kosher, compared with 18,000 in 1988. Much food—flour, rice, and other staples, and all produce—is kosher by definition, and need not bear a "hechsher," or kosher symbol, although a lot of it does. A hechsher can be as much an indication that a manufacturer thinks certification will attract customers as that it produces kosher food.

Commercial kosher certification in this country has come a long way from its beginnings, in the early 1920s, when shoppers had to look hard to see if a product was officially kosher. The inconspicuousness was intentional. With increasing waves of immigrants requesting kosher foods, established (and non-Jewish) food manufacturers recognized a new market to be tapped. But they didn't want to lose any customers. So they asked the Orthodox Union, based in New York and today the largest certifying organization in the world (it certifies food in seventy-seven countries), to devise a symbol that did not show the word "kosher" or betray its meaning to those who might prefer to avoid "Jewish food." The symbol—a U inside an O—is still in use. Today's hechshers are practically blaring by comparison, and many mainstream producers now spell out the words "pareve," meaning neither dairy nor meat, and "kosher" itself.

The labeling is useful not only to those keeping kosher but also to many others who choose or need to control their diet. Vegetarians know that a product marked "dairy" or "pareve" contains no meat, and vegans and people who are lactose-intolerant know that pareve foods contain no dairy products. Seventh-Day Adventists, who are often vegetarian, are an important part of the kosher market, as are Muslims: all forms of pork are both haram (not allowed in the Muslim diet) and non-kosher, or treif (literally "unfit"). Observant Muslims will buy kosher meat in the absence of a halal butcher.

People are turning to kosher food not just because of a revival in religious observance but because anyone buying food today is rightly concerned with safety, especially the safety of meat, and kosher certification requires careful inspection. Animals that are visibly ill before slaughter are forbidden. (This would have eliminated the "downer" cow, unable to walk, that was the one confirmed carrier of mad cow disease in the United States; other safeguards include the prohibition of stunning before slaughter, which can spread brain and spinal fluids to meat.) Some animals are further examined after slaughter. "Glatt," a word meaning "smooth," signifies that the lungs of the animal have been found free of adhesions indicating possible cancer or other systemic disease. An animal rejected as glatt can be qualified as (plain) kosher, but many slaughterhouses simply sell that meat as non-kosher, so by default all their kosher meat is glatt. Although "glatt" has no meaning outside the slaughtering process, in the 1970s it became generally used to mean "extra kosher," as Lisë Stern explains in her recently published How to Keep Kosher.

Kosher certification does not, however, offer many of the guarantees that health- and environment-conscious consumers might want. Kosher food need not be organic. There is no clear rabbinical stance on genetically modified organisms, even if in theory the manifold rules against anomalous foods would seem to forbid them. This is a natural concern for "advocates of eco-kashrut," as Stern terms them in her book. (With kashrut being adopted by many young Jews, there is of course an eco-kashrut movement; you can read about it at

And kosher food is often produced by multinational agribusinesses whose environmental and labor practices can be questionable. Hebrew National, for instance, known for its kosher hot dogs, is owned by ConAgra, a company practically synonymous with global agribusiness. (For reasons of slaughtering and certification methods, many Orthodox rabbis recommend against Hebrew National products.) Like all other industrially raised and packaged foods, kosher food can be full of trans fats (more unhealthful than butter, though pareve) and processed sugar. Lovers of "old" Coke take note: at Passover big-name sodas are made not with the usual corn syrup—cheap and insipid and, happily, not kosher for Passover—but with the far superior cane syrup.

Perhaps more surprising, certification rules seldom concern the conditions under which animals are raised, though the Torah does advocate the humane treatment of animals. Factory-farm veal, inhumane by almost anyone's standards, is officially kosher, although many rabbis recommend against consuming it or any other animal raised inhumanely. The Talmud does spell out the rules of slaughter. Shochets, trained slaughterers, must slit animals' throats cleanly and without hesitation, using a well-honed, nick-free blade. At the beginning of a slaughtering session the shochet blesses the process as commanded by God; the blessing is not for the animal or its life. Contrary to many people's belief, food certified kosher is not blessed by rabbis.

Apart from being assured of meat likelier to be safe, why bother buying kosher food, let alone keeping kosher? The answer for Jews is to obey God, pure and simple. As Judith Shulevitz, who is writing a book on the relevance of the sabbath in modern times, put it to me recently, keeping kosher is meant to "carve holiness out of the physical world." It is not meant to be justified by claims for food safety or superior ethics. Such justifications have been forwarded since at least the time of Maimonides, who wrote in the mid-1100s, while a court physician to the sultan of Egypt, that both Jews and Muslims prohibited pork because the pig's "habits and food" are "very filthy and loathsome." Finding logic in the rules of kashrut is a frustrating task, as the anthropologist Marvin Harris entertainingly recounts in his book The Sacred Cow and the Abominable Pig. Citing numerous examples of circular, anachronistic logic, Harris explains that attempts to apply modern knowledge of hygiene and disease and zoology to the Middle East of biblical times are usually fruitless. (Harris notes, for example, that the knowledge that undercooked pork may cause trichinosis dates only to 1859.)

In her seminal essay "The Abominations of Leviticus," from Purity and Danger, the anthropologist Mary Douglas discouraged theologians and anthropologists alike from using modern scientific thinking to justify biblical prohibitions. Douglas posited that what underlay the rules of kashrut was the desire to establish and maintain order (or "seder"). Kashrut was meant not to safeguard the health of Jews but to bring them closer to holiness, by keeping them separate from other tribes and religions.

The very root of the word "holiness," Douglas pointed out, means "set apart." She concluded,

The dietary laws [were] like signs which at every turn inspired meditation on the oneness, purity and completeness of God. By rules of avoidance, holiness was given a physical expression in every encounter with the animal kingdom and at every meal.

Keeping kosher is at heart a spiritual choice, then, and separation and the inexplicable are its essence. The practical consequences of that choice provide daily challenges, and daily connections to the spiritual.

The biggest challenge is the first: converting a kitchen. Stern gives friendly and practical instructions in her book, along with the advice that if you're thinking of making the switch, Passover is a good time to do it. Observant Jews must clean their kitchens top to bottom anyway, to excise all traces of chametz, or bread and leavened foods. Most American Jews, following the advice of U.S. rabbinical organizations, also use separate Passover dishes, like the ones my family hauled up from the basement before the first seder. These two new sets of dishes, one for milk and one for meat, are in addition to the two sets of dishes used the rest of the year. Jews in other countries simply kasher—or "make kosher"—their everyday dishes for the holiday, usually by immersing them in boiling water (Stern quotes an Israeli friend who asked, "Who had four sets of dishes?").

The annual ritual of cleansing and separation is a smaller-scale version of a changeover to kosher, a more-stringent procedure that requires days of pantry purging and thorough cleaning of cabinets and drawers; you must also boil metal cookware and make sure you have two of everything (wooden spoons, knives, broiling pans). Labeling cabinets and drawers is helpful, and so is color coding, a tradition familiar from the red (meat) and blue (milk) dish towels and soap pads of my childhood. Stern traces the widespread use of color coding to the soap manufacturer Israel Rokeach, who developed a kosher soap (made without animal fat) in his native Poland and produced blue and red versions of it in 1890s New York.

Not everything in a non-kosher kitchen can be converted. Most toaster ovens, for instance, cannot survive the scorching heat necessary to kasher them, as stoves and regular ovens can; buy a new one. With this requirement as with all others, Stern is careful to say, Consult a rabbi. There is no single authority and no one rule.

Stern leavens (if I may) the book with reminiscences of her childhood, when, as a displeased nine-year-old who liked bacon, she was made to participate in her parents' decision to go kosher, as part of an attempt to add meaning to their lives. I already knew Stern to be an expert baker; we met when she worked at this magazine, and we later collaborated on baking and candy recipes for a book I wrote on coffee. She's also an active member, with her husband and three children, of a Cambridge synagogue. Her account of how her initial resentment turned to acceptance and then to enthusiasm may mirror what others newly converted to kashrut feel.

Daily challenges become second nature; daily deprivations are surprisingly few. And habits become ingrained. My sister does not keep kosher—nor do I—but she recently told me that it would never occur to her to mix milk or butter with meat in her kitchen, and the only time I countenance it in mine is for the ultra-treif pork simmered in milk. My stepmother, who did not grow up in a Jewish home, chose to keep kosher when she married my father, and says that after twenty years the one rule of kashrut she still resents is not mixing milk and meat dishes in a single dishwasher load, which she finds both illogical and wasteful.

She enjoys experimenting with recipes in the Jewish cookbooks I've sent her over the years. The reigning queens of the genre, Joan Nathan, Claudia Roden, and Faye Levy, have written numerous books demonstrating the sometimes astonishing international scope of Jewish food, most but not all of it kosher. Judy Zeidler, a sophisticated cook and traveler, has written many books of up-to-date recipes that happen to be kosher (The Gourmet Jewish Cook, The 30-Minute Kosher Cook), taking the only sensible approach: her recipes are wide-ranging and good, and don't call for fake versions of ingredients like cream, butter, and bacon, which are almost always unsatisfactory and awful-tasting. Maggie Glezer, the author of the comprehensive Artisan Baking Across America, recently published A Blessing of Bread, with two dozen recipes for challah, and instructions for making matzoh—though you'd have to be very flexible in personal observance to call it kosher for Passover.

My favorite book on Jewish cooking, frequently in and out of print since its 1981 release, miraculously appeared in the mail while I was researching this article, in a fresh reprint with a slightly revised title: Classic Italian Jewish Cooking. The author, Edda Servi Machlin, grew up in Pitigliano, a small hill town in southern Tuscany, where her father was the rabbi and shochet. This is a great cookbook, on a par with Marcella Hazan's books in clarity and in promoting a wide understanding of and reverence for Italian food. It has inspired many of my travels throughout Italy, and I once made a pilgrimage to Pitigliano, which she lovingly evokes as a pre-war model of comity between Jew and gentile.

Machlin includes numerous Passover recipes, including chicken soup with peas and homemade egg noodles made with Passover flour, and a showpiece dish of lamb chops with chicken meatballs and spinach (the San Francisco author Joyce Goldstein fruitfully mined similar territory in Saffron Shores: Jewish Cooking of the Southern Mediterranean). But the annual conundrum that sends Passover cooks to bookstores is dessert, and Machlin supplied the cake that has become my family's favorite at seders—torta del re, or king's cake, an elegant almond torte that is fresh-tasting from lemon peel. It inspires that most desired end-of-seder-meal exclamation: "This doesn't taste like Passover!"

For a cake that will yield twelve thin slices, line the bottom of a ten-inch springform pan with parchment or wax paper, grease it, and coat it with matzoh meal (or bread crumbs outside Passover). Preheat the oven to 325° with a rack placed in the middle. Beat five egg whites with a pinch of salt until they are stiff, and set them aside. In a large bowl beat at medium speed five egg yolks, adding one and a quarter cups of sugar in a slow stream, until the yolks are lemon-colored, three to five minutes. Gradually fold in two and a half cups (ten ounces) of blanched almonds, chopped very fine but not ground, along with the grated rind of one lemon, a teaspoon of vanilla extract, and, if desired, a teaspoon of almond extract. The nuts will gum up the airy yolk mixture, but persevere; stir to make a coarse, hard paste. Work in a third of the beaten whites to lighten the paste, and then fold in the remaining whites as delicately as possible. Pour the batter evenly into the prepared pan and place in the center of the rack. Bake for one hour without opening the oven door. Then turn off the heat and leave the cake in the oven, with the door ajar, for ten to fifteen minutes. Remove the pan from the oven and invert it onto a cooling rack. When the cake is thoroughly cool (wait at least thirty minutes), release it upside down onto a serving plate. Sift confectioner's sugar (be sure it's kosher for Passover, meaning made with potato rather than corn starch) on top, and decorate with toasted sliced almonds if you like. The root of holiness may be separation, but this is a cake that can unite the most kosher-skeptical of cooks.