Of all the silent recipe-mistranslations a home cook can make, the salt one is the most damaging. Not because salt is special — flour density and oven inaccuracy do worse — but because salt error is concentrated. Twenty percent more flour spreads through a whole loaf; twenty percent more salt is right there on every bite, and there's no way to cook it back out.
The numbers
By weight, salt is salt. A gram of any sodium chloride is a gram of any other. The problem is that almost no home cook measures salt by weight. We measure by volume — pinches, teaspoons, tablespoons — and salts vary enormously in volume because of crystal shape.
- Table salt (fine, almost dust-like crystals): about 6 g per teaspoon.
- Diamond Crystal kosher (large flaky pyramids, the American restaurant default): about 3 g per teaspoon.
- Morton kosher (small dense flakes): about 5 g per teaspoon.
- Maldon flaky sea salt (large irregular flakes): about 2 g per teaspoon.
That's a three-times spread between the lightest and heaviest common kitchen salts. A tablespoon of Diamond Crystal weighs roughly half what a tablespoon of table salt does; a tablespoon of table salt weighs roughly three times what a tablespoon of Maldon does.
What recipes assume
Almost no recipe says which salt it's calibrated against. The convention is regional:
- American restaurant cooks and most modern American cookbooks (NYT Cooking, Bon Appétit, Salt Fat Acid Heat) assume Diamond Crystal unless otherwise stated.
- America's Test Kitchen and older American cookbooks often assume table salt or Morton kosher.
- British recipes default to fine sea salt, closer to table salt by weight.
- European recipes typically give salt by weight (in grams), which is the only honest way.
How to convert without breaking dinner
The safe rule is to convert by weight, not volume. Start from the recipe's implied salt:
- Identify what the recipe assumes (or guess based on its origin).
- Convert the recipe's salt amount to grams using the densities above.
- Convert that gram amount back to the volume of your salt.
Example: a recipe says “1 tsp kosher salt”, and you only have table salt. If the author wrote in Brooklyn, that's probably 1 tsp Diamond Crystal = ~3 g. In your table salt, 3 g is half a teaspoon. Use less than the recipe says, taste, and add more if needed.
The ingredient converter has separate entries for table salt, Diamond Crystal kosher, and Morton kosher — picking the right one and converting between weights makes this safe.
The forgiving direction and the dangerous direction
Going from a denser salt to a less dense one (table → kosher) under-salts your dish — easy to fix at the table. Going from a less dense salt to a denser one (kosher → table) over-salts your dish — almost impossible to fix. So when you're uncertain, err toward less salt and adjust at the end.
The honest fix
If you cook from a wide range of sources and you're tired of the mental conversion, the actual fix is to buy a digital kitchen scale and a kitchen tare bowl and add salt by weight. A 0.1 g resolution “jewellery scale” (cheap, and confusingly named) gets you the precision you need for small quantities. From that day, salt brand stops mattering and you're free to choose by texture and flavour rather than by what the recipe assumed.