Have you ever used Kosher salt in a recipe and found the end result to be like a salt lick and you couldn’t imagine how on earth a recipe tester could have not noticed how horribly, horribly oversalted the dish would end up? Let me guess: you were using Morton Kosher Salt. Guess what the recipe tester was probably using? Diamond Kosher Salt. And I know what you’re thinking: Now you tell me!
Believe it or not, I only learned about this disparity weeks ago but I had suspected something was wonky for a while. I use Diamond Kosher Salt so I hadn’t run into the issue but I’ve often received comments that people found even a lightly-salted dish way over the top. In short, Morton and Diamond are made differently; Morton salt presses salt granules into large flakes with rollers; Diamond, through a patented process, stacks salt pyramids to form a large crystal — one is dense, the other is like a snowflake. One is intensely salty for its volume, the other has an expected level of saltiness.
So how to adjust for this in recipes where one is measuring salt by volume? A cup of Morton’s salt can weigh almost twice as much as a cup of Diamond’s salt, and therefore taste twice as salty. The intrepid Jill Santopietro at Chow.com came up with the following equation simply by weighing the salts:
1 teaspoon fine sea or table salt = roughly 1 1/4 teaspoons Morton’s kosher salt = roughly 1 3/4 teaspoons Diamond Crystal kosher salt
“Uh, Deb, are we supposed to memorize that?” Of course not. Basically, you can think of a teaspoon of fine sea salt, regular old table salt or Morton salt as just about equivalent in salty impact. If you’d like to use Diamond kosher salt instead of table or sea salt in a recipe, use double. [Updated to clarify]
“But aack, this stresses me out because how am I supposed to know what a recipe tester used?” Here’s my advice: Pretend they used Diamond salt. You can always increase the amount of salt later (and hey, isn’t “salting to taste” the best way to cook, anyway?) but good luck scrubbing it out.