There are significant similarities and only minor differences between everyday table salt and kosher salt. A misconception of kosher salt is that it is consumed by only those that follow the Jewish food laws (that allow only kosher foods to be eaten). In fact, kosher salt is not named after those guidelines, and practice and does not conform to those standards. Instead, it got this name because it is used to cure meat in order to make the meat kosher.
Kosher salt is comprised of larger and corser grains than table salt. Table salt is a more refined salt with very small grain size. Due to the larger grain size, kosher salt is easier to pinch and measuring with your fingers, which is why it is a favorite for many chefs.
Table salt and kosher salt taste fairly similar to one another. However, table salt has a slightly metallic flavor due to the iodine that is added. Kosher salt, which does not contain any iodine additives, therefore tastes lighter and cleaner than table salt. Kosher salt tends to be less salty overall than table salt.
Kosher salt, as opposed to table salt, has no additives. Table salt, or iodized salt, often contains additives. Some common additives in common table salt include potassium iodide, sodium iodide and sodium iodate. Also, sodium silicoaluminate or sodium ferrocyanide is commonly added to table salt as an anti-caking agent and occasionally added to kosher salt.
There are no major nutritional differences between table salt and kosher salt. Too much of either salt can cause problems in the body, such as high blood pressure. Not enough salt can also be detrimental, as the body needs salt in order to regulate the cell's electrolyte balance.
Table salt is the most common form of salt for everyday consumption and is what most people use to season their dishes. Table salt is commonly used to add flavor to many various dishes and foods. Kosher salt is sometimes used by cooks as a replacement for table salt because of its particular taste. Kosher salt is great for curing meat because of its large surface area which allows it to absorb more moisture than other salts. Kosher salt is wonderful for bringing out other food's natural flavor and is also sometimes used as salt around the rim of a margarita glass. However, kosher salt is not an ideal ingredient for baking because of its absorbency traits.
In order to substitute table salt for kosher salt in a recipe, you need to make sure there is enough liquid to do so. Because kosher salt absorbs more water as compared to table salt, you will likely need to add additional water or other liquid to the recipe if you substitute. Also, because different brands of kosher salt come in many different sizes of grains, it is often hard to pinpoint the exact amount, such as a teaspoon, for a recipe. However, you will begin to get a feel for the correct amount if you use one brand consistently through trial and error.