I posted this after reading an old cookie recipe that called for what seemed like way too much salt. It turns out they were using Diamond brand rather than Morton brand. I’m pretty sure most of the country uses Morton, but chefs and writers in New York have access to Diamond and often write recipes with this larger crystal salt These days it’s often noted so that home cooks won’t use their usual Morton and add erroneously use twice as much.
Here’s what learned from reading Cook’s Illustrated.
Brands of kosher salt are different. Ordinary table salt weighs 10 oz. per cup; Morton’s Coarse weighs 7.7 oz. per cup; and Diamond Crystal Kosher Salt weighs 5 oz. per cup. Keep this in mind. If a recipe calls for kosher salt and the amount seems unusually large, the recipe may have been tested with a coarser salt such as Diamond.
The New York Times informed me that the salty chocolate chip cookies had been tested with Diamond Kosher, which is much less salty than Morton kosher. This explains why the cookies were so salty.