There are two major brands of kosher salt: Diamond Crystal and Morton. We have a longtime favorite—but we can tell you how to use both successfully at home.
Published Oct. 4, 2019. Appears in America's Test Kitchen TV Season 21: Salmon Steaks Done Right
Of all the ingredients we call for in our recipes, salt might be the most important. It acts not only as a seasoning but also as a flavor enhancer that brings out the best in other ingredients: A sprinkle of salt makes a tomato’s flavor more vibrant and adds complexity to caramel. Salt can also improve the texture of some foods: Dried beans soaked in a saltwater brine are less likely to burst, and turkey meat and skin rubbed with salt before roasting will be juicier and crispier, respectively. We also use salt to pull excess moisture from vegetables such as cabbage and eggplant before adding them to slaws or stir-fries.
While we call for both table and kosher salt in our recipes, we generally prefer the larger, coarser grains of kosher salt for rubbing onto meat or sprinkling over foods. A handful of smaller companies and artisans manufacture kosher salt, but two major brands, Diamond Crystal and Morton, dominate the American market. While both are labeled kosher salt, the grain sizes of these two products are surprisingly different, so they’re not interchangeable. To make sure your food isn’t bland or overseasoned, especially when using kosher salt in a large quantity to make a brine or a salt rub, it’s important to know how the two major brands differ.
Chemically, all salt is sodium chloride (NaCl). Both table and kosher salt can be harvested from either seawater or underground salt beds; Diamond Crystal and Morton both harvest their salt from underground. According to representatives from both brands, the first step in their respective salt-making processes is pumping water into the salt beds to form a brine, which is then forced to ground level. The companies evaporate the brines using strictly controlled methods that determine the size, shape, and density of the salt crystals.
According to Erica Williams, a senior manager on the consumer insights team at Morton, Morton’s brine is pumped into huge commercial vacuum evaporators that are about three stories high. As the pressure in the vacuum decreases, the brine boils at progressively lower temperatures, saving both time and energy. To give Morton kosher salt its distinctive size and shape, Williams said, the remaining salt particles “are pressed through high-pressure rollers and flattened into large, thin flakes.” Finally, the flakes are run through screens to ensure a uniform shape.
The process used to make Diamond Crystal salt differs from Morton’s process in a few important ways. Diamond Crystal is the only company in the United States to use the Alberger process, a technique developed in the 1880s tha...
The mission of America’s Test Kitchen Reviews is to find the best equipment and ingredients for the home cook through rigorous, hands-on testing.
Kate is a deputy editor for ATK Reviews. She's a culinary school graduate and former line cook and cheesemonger.