100% pure is just that. It is the essence of pure salt straight from the Mediterranean Sea. It is slowly evaporated and hand picked from the pools and packed just as it came from the Sea. There are no chemicals or preservatives of any kind and, of course, no added iodine.
It does tend to be a bit "sticky" compared to salt you would buy from the major chemical companies like Mortons.
Kosher salt is certified Kosher and it is more free flowing and uniform like you would expect from grocery store salt. It does have one natural additive to prevent caking. It does not have any iodine added and has a wonderful taste.
The 100% pure is our favorite variety with its imperfections and amazing taste. It is easy enough to remove caking by shaking the salt in the container before use.