What’s the difference between table salt and kosher salt?
At chow.com, Jill Santopietro explains the difference between common salt types–table salt, sea salt, and kosher salt–and why it matters:
All salt, whether fine or coarse, sea or table, is sodium chloride. Five grams of coarse sea salt is as “salty” as five grams of fine salt. Sea salt often contains minerals picked up from the ocean, while table salt might contain additives such as iodine or anticaking agents. Sometimes these flavors are detectable.
The main difference lies in the crystal shape. Grains of table salt or fine sea salt are small and densely packed; kosher and coarse sea salts are large flakes with more air between them. This means that a tablespoon of fine salt weighs more (and is therefore saltier) than a tablespoon of larger salt crystals.
My rule of thumb? If the recipe gives a measurement, you should use the type of salt it calls for. If it doesn’t specify, as in “1 tbsp salt,” use table salt. A measurement for kosher salt is tricky, because different brands are more or less dense.
When in doubt, add salt “to taste.” In fact, if the salt is in the recipe as a seasoning, you should always adjust it to your taste. It’s only when salt is used mainly for it’s food chemistry properties–as in baking–that you must measure carefully.