What’s the difference between sea salt and rock salt? | casaveneracion.com

What’s the difference between sea salt and rock salt?

The earth as we know it today didn’t look the same millions of years ago. What used to be seas have dried up and are now covered with rock and soil. We know them today as subterranean or underground salt mines which have enough rock salt to supply man’s needs for the next so many centuries. So says a documentary on TV recently (Discovery Channel, if I remember correctly) which showed the locations of the largest underground salt mines in the world.

Did I say these salt mines can supply mankind with rock salt for the next so many centuries? Yes, rock salt; not sea salt. There is a difference. Sea salt is made by drying out sea water. So, the cheap rock salt sold in markets comes from the underground salt mines. The more expensive sea salt that we find in gourmet shops comes from the sea. Chemically, there’s not much difference as they are both more than 99% sodium chloride.

That’s sea salt sprinkled on the fish in the photo. We bought a bag just to try it out as some claim there is a difference in “mouth feel” although I can’t say that I’ve noticed. There are also claims that because salinity and presence of other minerals vary from sea to sea, the flavor of sea salt differs depending on which sea water the salt was dried out from. I’ve only tried one bag of sea salt so I can’t comment on the difference of flavors. If that makes me ungourmet, never mind.

Now then, sea salt… rock salt… where does table salt fit in? And kosher salt, for that matter?

In its most common meaning, table salt is refined rock salt. If iodine is added, it is iodized salt. During the term of President Fidel Ramos, one of his projects was the marketing of cheap iodized salt for the benefit of communities that have little access to food that are naturally high in iodine (i.e., seafood). Iodine, according to studies, helps prevent thyroid problems, and even mental retardation and low I.Q.

If both iodine and iron has been added, it is double-fortified salt.

What about kosher salt? The grains of kosher salt are not as fine as that of refined salt but they are not as large as rock salt either. Kosher salt grains are rather flat. Aside from the shape and size, is there any other significance? Note these two conflicting claims.

First from the Food Network.

Kosher salt takes its name from its use in the koshering process. It contains no preservatives and can be derived from either seawater or underground sources. Aside from being a great salt to keep within arm’s reach when you are cooking, it is particularly useful in preserving, because its large crystals draw moisture out of meats and other foods more effectively than other salts.

The second is a “citation needed” paragraph from Wikipedia.

The term “kosher salt” derives not from its being made in accordance with the guidelines for kosher foods as written in the Torah (nearly all salt is kosher, including ordinary table salt), but rather due to its use in making meats kosher, by helping to extract the blood from the meat. Rather than cubic crystals, kosher salt has a flat platelet shape. This is done in some salts by adding yellow prussiate of soda (sodium ferrocyanate). Because kosher salt grains are larger than regular table salt grains, when meats are coated in kosher salt the salt does not dissolve readily; the salt remains on the surface of the meat longer to draw fluids out of the meat.

Too much salt information? Well, it appears that the usefulness of salt is not limited to food and cooking. See the sixty uses of table salt.


  1. dyna says

    thanks for the info. spending some of my summer vacations when i was a kid in Neg. Occidental I often see people from nearby bay bay (shorelines) drying out sea water in salt beds. and they sell it cheap like 50 per sack. it was fascinating how they do it.

    • Connie says

      Wow, that would be a great subject for photography! Just like the Salinas salt spring in Nueva Vizcaya. :)

      • Beth says

        Ms.Connie, you dont have to go that far to see salt beds.If you go to Cavite City in the height of summer, you will be passing by a few remaining salt beds right before you enter the City.

  2. says

    in a raw food workshop, i got acquainted with the pink himalayan salt and they are actually very good. now, when i feel like indulging i would have a freshly baked bread, butter and the himalayan salt :)

    • Connie says

      I’ve always wondered why it’s called Himalayan salt when it’s mined some 300 km. from the Himalayas.

  3. Natz SM says

    There was a time I was obsessed with different kinds of salt that I even asked my relatives and friends from abroad to bring me different types of salt as their pasalubong to me- Hawaiian sea salt, smoked sea salt etc.

    I really couldn’t tell the difference between the taste of the “natural” salts although they were indeed differences in mouth feel- like if you were to sprinkle them on a piece of bread with butter, your could feel the the courser salts.

    In making TOCINO, I remember my Lola specifying the use of plain salt(meaning the salt that had not been fortified with IODINE). Somehow, if one uses iodized salt, the taste of iodine will be evident in the tocino- makes sense so I just follow her instructions.

    I found this article about salt which might interest everybody.


    • Connie says

      “like if you were to sprinkle them on a piece of bread with butter, your could feel the the courser salts”

      Because they don’t dissolved totally? I’m not so sure I want to bite on undissolved salt.

      • gigi says

        hmm matry nga ang diff salts.. i have always cooked with table salt, and then after watching some cookery shows, and noticing they use a lot of sea salt or kosher salt, i swapped to sea salt.. i think there is a difference to taste and how they flavor the food?
        uum or should i say spice the food? ano nga ba sya? flavor or spice? hehe sorry out of topic ba? hello ms connie :-)

        • Connie says

          Table salt, sea salt and rock salt all taste the same to me. Kosher salt is fashionably expensive as the choice of most TV chefs.

  4. says

    Thanks for the article, would just like to point out that there’s no conflict in the two statements regarding to the kosher salt. Both state that the term “kosher salt” or “koshering salt” are not referring to the state of the actual salt being kosher (which I’d guess all pure salt is) but rather to the effect the salt has on meats, etc, being that it is an essential part of the process to make them kosher. Thus, “koshering salt” is a more accurate (and less confusing) name for it than just “kosher salt”.