Sodium chloride. The term “curing salt” is sometimes applied to sodium nitrite and other chemicals. There are several kinds of salt, depending on how it is mined or processed; most salts are not pure sodium chloride. Any natural salt can be used for curing meats. Salt also comes in various grains, from fine to large chunks commonly known as ice cream salt. Any of the forms can be used in a brine, provided it is well mixed, but salts for dry cures work best in a fine grain.
It has been noted that man did not use sodium nitrite and other minerals in his cured meats until quite recently. This is not the whole story. Until recently, these minerals were not removed from natural sea salt before it was used for curing meats. Modern man is, in short, taking sodium nitrite and potassium nitrate and other minerals out of salt—and then putting them back into the salt used to cure meats. In any case, my favorite salt for curing and table use is unrefined sea salt, simply because it has good flavor. Sea salt is, however, too expensive these days for large-scale meat curing.