Consider kosher salt: large, flaky, white grains that dissolve slowly in cooking. If you like to cook, you probably have a box of Morton or Diamond kosher salt in your cupboard, and if you are a chef, a small mountainous peak is likely sitting in a crock that you keep within arm’s reach in the kitchen at all times. It is one of the most ubiquitous ingredients in the cooking world — but it’s also one of the most misunderstood: All salt can be kosher (if it’s produced under kosher supervision) but not all kosher salt is kosher.
Salt has been used since ancient times to preserve food, and Jews have used it since the time of the Temple to remove blood from meat or “kasher” it, according to Gil Marks, author of the “Encyclopedia of Jewish Food.” Specifically large-grain salts were used as they could be washed from the meat’s surface without making it too salty.
Despite its status as a luxury product elsewhere in the ancient world, this type of salt was abundant in ancient Israel. The salt mines and salty seas of the region helped establish it as a center of the salt trade.
The term “kosher salt,” however, is a 20th-century American construction. “Jews were obviously using the product long before,” Marks said. “It’s not really ‘kosher salt’ — it’s koshering salt.” Up until the 1950s (when packaged kosher meat became available) kosher-keeping home cooks purchased this coarse salt to use in their kitchens to remove blood from the meat they served to their families.
The word came into public consciousness when companies sought to cash in on the wave of Eastern European Jews who immigrated to the U.S. at the end of the 19th and beginning of the 20th centuries. At the same time, the American market moved from purchasing their ingredients (including salt) by the pound, out of large barrels, to buying packaged goods that started appearing on the shelves after World War I.
“Certain companies started marketing to Jews,” Marks explained. At first these were Jewish companies, including Rokeach and Manischewitz; later, non-Jewish companies, including Diamond and Morton, picked up on the trend.
Diamond advertised their kosher salt product repeatedly in the Yiddish Forverts in the 1920s, and Morton went so far as to produce boxes labeled in Yiddish to appeal to the Jewish market. These types of boxes were marked “kosher salt” rather than “koshering salt,” and the new term stuck.
Still, it wasn’t until much later that kosher salt was marketed outside the Jewish community. That came in the late 1960s, according to Mort Satin, the vice president of science and research for the trade organization, The Salt Institute. (Satin goes by another name, as well: the “Salt Guru.”)
Beginning then, “the only superlative in salt talk was kosher salt,” he wrote in an email to the Forward. Chefs began to favor it because its large grains and slowness to dissolve lent a light crunch to dishes. Kosher salt also lacks the additives often found in table salt, like iodine, which many chefs say imparts an unpleasant flavor.
Satin is certain the word “kosher” also lent an air of exoticism to some ears, which furthered its popularity. But how did kosher salt transition from tucked-away restaurant kitchens to the spotlight? Food television, Satin posited.
“So much of TV cooking is visual,” Satin reasoned. “Shaking a little salt shaker could not compete with dipping into a bowl of kosher salt and casting the large, very visible salt crystals across the dish like Toscanini waving his baton across the orchestra. Flair, panache… magic.”
Rachel Tepper is an associate food editor at The Huffington Post, where she writes about food trends and restaurants.