A Tablespoon of Salt Isn't a Tablespoon of Salt

Photo by Lexlex, CC BY-SA 4.0, via Wikimedia Commons

Different salts have very different crystal shapes and densities — fine table salt packs tightly into a measuring spoon, while flaky kosher salt or coarse sea salt leaves more air between larger crystals — so the same volume measurement can hold roughly double the actual salt depending on which one you use. A recipe written for one brand of kosher salt can end up badly over- or under-salted with another. Weighing salt on a scale (or converting carefully between specific brands) is far more reliable than trusting a teaspoon measurement across salt types.