Rock salt and table salt differ in flavor due to their processing and mineral content; rock salt often has a more complex, mineral-rich taste compared to table salt's pure sodium chloride flavor.
The primary difference in flavor between rock salt and table salt stems from their composition and processing. Table salt is typically mined, heavily processed to remove impurities, and often has iodine added. This process results in a nearly pure sodium chloride (NaCl) product. The addition of anti-caking agents can also subtly affect the taste.
Rock salt, on the other hand, is mined directly from underground deposits and is often less processed. This means it retains trace minerals like calcium, magnesium, potassium, and iron. These minerals contribute to a more complex and nuanced flavor profile. Some people describe rock salt as having an earthier or slightly sweeter taste compared to the straightforward saltiness of table salt. The larger crystal size of rock salt can also affect how the salt is perceived on the tongue, as it dissolves more slowly.
When using rock salt, especially in a grinder, start with a small amount and taste as you go. The mineral content can vary between different rock salt sources, so it's best to adjust the seasoning to your preference.