Kosher salt is preferred by many chefs due to its large, coarse crystals, which provide better control when seasoning and dissolve quickly, and because it typically lacks additives like iodine, resulting in a purer, cleaner flavor.
Kosher salt's popularity among chefs stems from several key characteristics. First, its large, irregular crystal structure makes it easier to pinch and distribute evenly over food. This tactile feedback allows for more precise seasoning compared to finer table salt. Second, kosher salt dissolves rapidly, ensuring even flavor distribution throughout the dish. This is especially important in applications like brining or seasoning large cuts of meat. Finally, most kosher salt brands are free of iodine and other additives commonly found in table salt. Iodine can impart a slightly metallic or bitter taste, which chefs often want to avoid to maintain the purity of the dish's flavors. The absence of additives also prevents potential discoloration in certain recipes.
When substituting kosher salt for table salt in a recipe, remember that they are not a 1:1 replacement. Kosher salt is less dense, so you'll need to use approximately twice as much kosher salt by volume to achieve the same level of saltiness as table salt. Always taste and adjust seasoning accordingly.