Salt is chemically the simplest ingredient in the kitchen and the most treacherous to measure by volume. The reason is geometry: crystal shape determines how much salt fits in a teaspoon, and the two big kosher brands disagree wildly.
The numbers
| Salt | Weight per tsp | vs table salt |
|---|---|---|
| Table salt | 6.0 g | reference |
| Fine sea salt | 7.0 g | +17% |
| Morton kosher (dense flakes) | 5.5 g | −8% |
| Diamond kosher (hollow pyramids) | 2.8 g | −53% |
A recipe written with Diamond kosher and measured with table salt lands at double the intended sodium — the classic "why is this inedible" scenario, and it runs in both directions.
Why the shapes differ
Diamond Crystal's flakes are hollow pyramids (formed under pressure and broken apart) — lovely to pinch, enormous to measure. Morton's kosher is denser rolled flakes. Table salt is fine cubes that pack tight. Same compound, same salinity by weight — the teaspoon is lying because the crystals hold different amounts of air.
The fixes
- Weigh salt — by weight, all salt is salt (minus iodine additives). 6 g is 6 g in every brand.
- Brand-match recipes: most American recipe developers use Diamond kosher; the "1 tbsp kosher salt" of a brine assumes its lightness.
- When substituting volume: table salt for Diamond kosher = use half the volume; Morton for Diamond = about double.
- Season by hand and taste — pinch-distributed kosher salt is the chef's tool precisely because the fingers out-measure the spoon.
Salt is the ingredient where this database's whole philosophy is most visible: the volume measure carries air, the weight carries truth — and dinner tastes the difference.