Coarse salt is a generic category description for salt that isn’t ground as finely as table salt is, and therefore can’t be shaken out of a salt shaker.
In this category would be rock salt, kosher salt, Maldon salt, various sea salts, etc.
The salt can come from ground or seawater.
Coarse salt usually has no iodine and no anti-caking preservatives added. Consequently, it can usually be used for pickling and canning. (Additives would cause cause your preserve to darken and go cloudy.)
It can be used for:
- salt crusts on foods;
- salt beds for oysters;
- margarita glass rims;
- coating pretzels.
In Italy, coarse salt is used in boiling water for pasta.
When used at the table as a condiment salt or finishing salt, coarse salt can add a crunch to food because it stays on the surface of a food for a while, rather than getting drawn all the way through, thus giving a contrast of tastes and texture. Some coarse salts such as rock salt would be generally be considered too coarse for table use, while others such as Maldon salt are meant for table use.