Yes, they are all types of salts. Removing liquid from the eggs making them have lees mosture so they get harder. The best cure that i have found is Bobs in the Resource Center. Just did about #20 pounds and the egges came out very nice. When you cure eggs they must not of been frozen. When they have been frozen it breakes the sides of them, making them leak and mile out very fast. After they have been cured they are smaller in size and can take being frozen,,