Why Is Kosher Salt Called “Kosher” Salt?

According to Morton Satin of the Salt Institute, the industry’s trade association, the name stems from the salt’s original use: to draw blood out of meat so that it meets the dietary rules set by Jewish law. (The Bible sanctions against ingesting blood and commands the use of salt to draw out the blood.) While table salt’s fine grains would disintegrate if slathered on a side of beef—potentially making for one very salty brisket—kosher salt’s larger crystals wouldn’t all dissolve. “Both the blood and salt wash off,” says Satin. The process is sometimes called koshering.

Kosher salt, like most mass-produced salts, does also happen to be kosher—that’s to say, it contains no additives and has been certified as kosher by a rabbi or an authorized organization. (To debunk one common myth, kosher foods do not receive a rabbi’s blessing.) Sometimes small producers don’t bother having their products certified. Salts that have been certified kosher are marked as such with a circled K or U on the label.

Kosher salt has a coarse texture, which makes it easier to gauge and control how much you’re using. That makes it more popular with chefs than table salt. Some say it has a cleaner taste than table salt. And those large crystals sure do perch up well on a margarita glass.

But bakers beware: Kosher salt weighs at least 26 percent less by volume than table salt. That means if you use a 1/4 teaspoon of kosher salt in a recipe calling for 1/4 teaspoon of table salt, you’re adding too little. And different brands of kosher salt have different-size flakes, says Susan Reid, editor of The Baking Sheet newsletter from King Arthur Flour. That makes it hard to come up with an absolute rule of thumb for substituting kosher salt for table salt in recipes. Reid recommends this method: When a recipe calls for a teaspoon of table salt (or 1/4 or 1/2, etc.), use a rounded teaspoon (or 1/4 or 1/2, etc.) of kosher salt. The CHOW test kitchen, which always uses Diamond brand kosher salt, follows a 1-to-2 ratio of table to kosher salt.

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