Isn't necessarily Kosher, but is called that because it's used to prepare Kosher meats. The mineral salt has a cubic crystal shape. A grain of kosher salt is composed of many cubes stuck together. With its large surface area, it can absorb more moisture than a similar sized cubic salt crystal. This makes it ideal for curing meats, which involves absorbing blood from the raw meat. Use a little less when using this in place of the others.