Buzz
In reality, not much. Both salts consist primarily of sodium chloride. The U.S. government mandates that all food-grade salts contain at least 97.5% pure sodium chloride, meaning that salts in the U.S. (and most developed countries) are essentially identical in composition.
However, table salt typically includes additives like anti-caking agents (such as calcium silicate or sodium ferrocyanide) and iodine. Kosher salt, by contrast, generally lacks these additives, though some brands may include a small amount of anti-caking agent, but it is usually in much smaller quantities compared to table salt.
The most noticeable distinction between kosher salt and regular salt lies in their crystal sizes. Under a microscope, table salt’s crystals are finely milled into small cubes, whereas kosher salt is coarser, less refined, and features a more irregular crystalline structure.
The difference in grain size is why Kosher salt is named as such. Contrary to popular belief, Kosher salt isn't called “Kosher” because it’s certified as such. Instead, it earned the name because it was traditionally used in the koshering process, particularly to draw out surface blood from meat. Finer salts, like table salt, dissolve too quickly and tend to penetrate the meat, while larger grains of salt can absorb the blood and be rinsed off more effectively, leaving the meat less salty.
Purchasing Kosher salt doesn’t automatically mean it’s certified kosher (though most commercially produced food-grade salts are certified). To check if your salt is certified kosher, look for a K or U symbol inside a circle on the container. If it's there, the salt is kosher, regardless of its grain size or added ingredients.
