1 teaspoon of table salt is equal by weight to 1 ½ to 2 teaspoons of kosher salt, depending on the brand.
A ½ teaspoon less or more of salt can make a great deal of difference in cake batter or bread dough. If you swap out the type of salt listed in a recipe you’ll need to weigh your ingredients to be sure you’re adding the same amount of salt. Salt crystals differ in shape and size and the various types will melt at differing rates. Choose a lighter, smaller crystal like table salt for baked goods and larger grains or flakes as a finishing salt.
Table Salt – 1 tablespoon weighs 20 grams
Morton Kosher Salt – 1 tablespoon weighs 15 grams
Diamond Crystal Kosher Salt – 1 tablespoons weighs 10 grams
Granulated Sea Salt – 1 tablespoon weighs 20 grams
Flaky Sea Salt – 1 tablespoon weighs 10 grams
Adding a hint of salt to batter won’t give cake a salty flavor. Rather, salt reduces bitterness and allows sweetness to come forward, producing a more well-rounded flavor. Same is true with bread dough, just a little salt takes the flavor from flat to full.
Salt also affects the tenderness of a baked good. Salt molecules form strong bonds with flour proteins, causing the gluten molecules to become less mobile, which, in turn, makes the dough or batter tighter and more elastic. This is a desirable trait in a bread dough, but is not desirable in a cake batter.
Salt “denatures”, or loosens up, egg proteins. Add a little salt to egg wash to thin it down. A thinner egg wash is easier to brush onto bread or pastry for a glossy finish.
Testing results (not mine)
A pound cake was baked as a control focusing only the four original ingredients and the reverse creaming method.
For the next test, ½ teaspoon of table salt was added to the batter. The cake with the added salt baked up higher due to the stronger gluten in the batter, and had a noticeably more chewy bite. The flavor was better than the first cake, less flat and more well-rounded, but the loss of tenderness was not good.
Reduced the amount of salt to ¼ teaspoon for the third test. Improved the flavor, yet keep the tenderness of crumb.
*Recommended that salt and leavener be mixed with flour before other ingredients are added for a more uniform mixture.