Sodom and Gomorrah are burning, and the people are fleeing. Amidst the chaos, one disobedient refugee makes a fatal mistake. Lot’s wife turns back to gaze upon the ruins of her city—and meets swift retribution. In an instant, she is turned into a pillar of salt.
Even by biblical standards, the story is a weird one. Yet seen through a certain lens, it follows a kind of poetic justice. For lingering on the sordid stuff of earthly life, Lot’s wife is turned into the one substance the Torah considers most pure and sacred. God instructs Jews to include salt with all offerings: “You shall not suffer the salt of the covenant of your God to be lacking from your offering: with all your offerings you shall offer salt.” (Leviticus 2:13). This saline tradition lives on today, in the modern Jewish practice of kashering, in which salt is used to draw blood from an animal’s flesh, and in the Hamotzi—the blessing over bread in which challah is dipped in salt before eating.
Salt is an essential and universal part of the human diet, cleansing food by destroying harmful pathogens (one of the reasons commonly given for the rim of salt on your margarita glass). Food philosopher and writer Michael Pollan describes it in Cooked as “the only mineral we eat on purpose.” In Judaism, it also imparts a spiritual purification. “You’re salting your meat because you want to flavor it, yes, you want to preserve it, yes, but you’re also salting it in accordance with your religion,” says Jordan Rosenblum, a religion and food scholar at the University of Wisconsin. “The practice of salting meat to make it kosher ended up giving salt a special, extra connotation of holiness.”
The symbolism doesn’t end there. “In the ancient world, when you made a treaty with a human or a deity, you didn’t sign it,” says Rosenblum. “You had a sacrifice to seal it.” In this way, salt used for sacrifice came to represent sacred bonds. In the most famous of these bonds, God makes a promise to David that he and his descendants will hold the throne for all of time and calls it a “salt covenant.”
There is another reason that salt shows up so often in Jewish tradition. Israel, it turns out, is salty. Even today, the earth in that part of the world gleams with saline crystals. Mountains spiked with salt pillars line the modern-day region of Mount Sodom, a ten-mile stretch bordering the Dead Sea. (The Dead Sea, by the way, is ten times saltier than any other ocean; today its edges curl into crests of salt that look like glittering waves of foam.) “Sodom salt” is so caustic, the Talmud warns those who use it to wash their hands to avoid irritation.
Outside ancient Israel, salt was often so rare that it was used as currency. The word “salary” (salt money) derives from the fact that Roman soldiers are said to have been paid in cakes of salt. The phrase “worth your salt” has the same origin. But in Israel, salt was a material as common and necessary as air. Thanks to the area’s salty seas and salt mines, salt routes crisscrossed Israel and helped establish it as a center of the medieval salt trade. “Israel was blessed with an abundance of salt, from both sides”—the Mediterranean and the Dead Sea—writes the late Gil Marks in The Encyclopedia of Jewish Food. “Thus salt, although still precious, was never unobtainable or exorbitantly priced in Israel.”
When they left the Mediterranean for all corners of Europe beginning in approximately the first century CE, Jews brought with them their practice of kashering meat. In addition to being spiritually sanctioned, salt also became key to the most common form of food preservation: pickling. Jews pickled cod, herring and vegetables to make them last through the harsh winters. “In that way, European Jews are really not any different than most poor people who lived in pre-modern conditions,” says Hasia Diner, professor of American Jewish history at New York University.
By the time Jews settled in America centuries later, their salty fare was no longer a necessity. “It became a taste that they obviously liked and that came to be associated with them,” says Diner. Jewish immigrant cuisine meant lox, bagels, pastrami, corned beef, whitefish, pickles, “tastes that were very assertive and very pungent—garlicky, salty, pickled foods,” says Jonathan Brumberg-Kraus, professor of religion at Wheaton College. “Salty foods were a way of asserting Jewish identity.”
This would become a problem. As waves of Jews and other immigrants began filling grocery stores with strong-smelling, fermented, seemingly near-rotten foods, delicate American noses were shocked. “The Jewish children suffer from too many pickles,” wrote Boston dietician Bertha Wood in her 1922 book Foods of the Foreign-Born in Relation to Health. “The excessive use of pickled foods destroys the taste for milder flavors, causes irritation, and renders assimilation more difficult.”
Efforts to sanitize the foods of immigrant Jews backfired. With the rise of the refrigerator, foods like salmon could now be easily pickled in a light salt brine (as opposed to the lengthy process of layering fish in barrels with dry salt). Thus began the rise of what are now some of the most iconic Jewish-American foods: corned beef, pastrami, lox. Add some salt-crusted bagels and a fresh kosher spear, and voilà: The deli was born, carved from a foundation of salt.
Yet a fortuitous advertising decision was responsible for Jewish salt’s biggest boon. Before the advent of the deli, Jews had continued to kasher their meat at home using the aptly named “koshering salt.” Large-grained and flaky, it was particularly handy for pulling the blood out of meat. But in the 1960s, two companies—Morton and Diamond—had the brilliant idea to begin marketing the same salt beyond the Jewish community, calling it “kosher salt.” Amazingly, the name stuck.
“People loved it for the panache,” explains Mort Satin, vice president of science and research at the trade organization The Salt Institute. “They love dipping their hands into a bowl and grabbing a couple fingerfuls of it. On the food channel you certainly never see a chef with a saltshaker—there’s not very much style associated with that.” Now, kosher salt is a pantry staple and necessity for chefs the world over.
In Jewish circles, salt remains just as essential as it was in ancient times. While it’s not used for animal sacrifices or as an alternative to a paycheck, the white stuff still makes a key appearance in prayer and is every bit as common on the Jewish table. “Can you imagine Jewish food without it?” asks Brumberg-Kraus. Salt might be seen as helping Jews preserve not only their meat and vegetables, but also their most prized traditions.