Salt has a rich history, and when you put it on food to add flavor, it’s no wonder this spice has been coveted the world over. All salt originated in the sea, but since then, various types of this seasoning have undergone natural processes that make some salts better than others for certain uses. In this article, we’ll explore some different types of salt and specifically discuss why the Kosher or “clean” variety is often better for barbecue rubs than its iodized cousin.
The sea is where it all begins. Salts from the ocean occur when evaporated water leaves minerals behind, much of which is NaCl. Naturally, these salts could also contain other minerals such as magnesium, calcium, and fluoride and even trace elements such as metals, microorganisms, and pollutants. Today, sea salts are made by humans in shallow ponds, and they are often best for seasoning and pickling.
The two most popular types of NaCl of which you are probably familiar are table and Kosher salts. The table variety is often iodized for nutrition, as potassium iodide has been added to the seasoning since 1924 to prevent the onset of goiters. Anti-caking agents are usually added as well to make it easier to sift, which makes it a good choice for shakers.
You may find anti-caking agents in the clean version as well, but there will not be any iodine. Clean NaCl often comes as larger grains than what you’d normally find in shakers on a restaurant table. Chefs often prefer this, because these grains are much easier to pinch and season.
Clean salts are better for barbecue rubs for a few reasons. Firstly, they are courser. You can get the same benefit from sea salts as well, but your preference for purity and consistency of crystal sizes may steer you towards the clean salts, as sea salts can often contain impurities as mentioned above. Also, clean NaCl does not contain iodine, and you may not think this is a big deal, but iodine (or potassium iodide as found in table varieties) can actually lead to discoloration of the rib meat.
What you want to look for in a good rub are nice-sized crystals that will bite into the rib meat when applied. Kosher crystals are often produced in a way that yields this effect, making them ideal for barbecue rubs. While sea salts also have nice-sized crystals, they can also have smaller crystals as well, and this inconsistency may not be ideal. Table salts are too small to use effectively for a rub.
There are, of course, other types of salts, including brines, curing salts, seasoned salts, pickling or canning salts, and saltpeter, not all of which are NaCl but will usually yield similar flavors. For barbecue rubs, though, the takeaway is that you want a pure, decent-sized crystal that is going to work best in the cooking process by doing only one thing, and that is bringing out the flavor of your rib meat. Clean salts will do just this without adding impurities that might change the color or flavor of your barbecue.