Kosher salt and table salt are the same thing chemically. Gram for gram they taste equally salty. The difference is that a tablespoon of fine table salt weighs roughly 18 g while a tablespoon of coarse kosher salt weighs about 8 g, so swapping them spoon for spoon can more than double the salt in your pot.
That one fact explains almost every “this recipe was way too salty” complaint in the comments of any American food blog read by someone cooking in a kitchen with a different box on the shelf.
Here’s what actually changes between the three salts most home kitchens end up owning, and which one wins for which job.
The density gap, in numbers you can act on
Salt crystals differ in shape. Table salt is milled into tiny dense cubes that pack together with almost no air between them. Kosher salt is made in larger, irregular, hollow-ish flakes that trap air, so a spoonful of it is partly empty space.
Approximate weights per level teaspoon:
- Fine table salt: about 6 g
- Morton-style kosher salt (denser flakes): about 4.8 g
- Diamond Crystal-style kosher salt (light, hollow flakes): about 2.8 g
- Fine sea salt: about 5 to 6 g, close to table salt
- Maldon-style flaky salt: about 2 to 2.5 g
Two brands both labelled “kosher salt” can therefore differ by nearly a factor of two from each other, which is the part most people miss. It isn’t table versus kosher. It’s dense versus airy, and the label rarely tells you which you bought.
I learned this the annoying way. I doubled a focaccia dough one Sunday, ran out of kosher salt halfway, and topped up with table salt measured by the same spoon. The rosemary focaccia that came out was edible only in very small pieces with a lot of water. About 9 g of extra salt in a dough that wanted 12 g total.
Weigh it and the whole problem evaporates
A kitchen scale that reads in single grams costs less than two bags of decent coffee and removes this entire category of mistake. Recipes that give salt in grams are telling you the truth. Recipes that give it in teaspoons are guessing about your box.
| Salt | Weight of 1 tsp (approx) | Volume needed to equal 1 tsp table salt (6 g) |
|---|---|---|
| Fine table salt (iodised or plain) | 6 g | 1 tsp |
| Fine sea salt | 5.5 g | a scant 1 1/4 tsp |
| Morton-style kosher | 4.8 g | 1 1/4 tsp |
| Diamond Crystal-style kosher | 2.8 g | a heaped 2 tsp |
| Maldon-style flaky | 2.2 g | about 2 3/4 tsp (don’t do this) |
These are rounded averages. Humidity changes them slightly, and how hard you press the spoon into the box changes them more than humidity does.
The rule I use: if a dish is seasoned and then can’t be fixed (bread dough, a brine, a cured thing, anything baked), I weigh. If I can taste and adjust as I go, like a slow beef stew, I use my fingers and my tongue and never touch the scale.
Iodised salt: where you’d genuinely notice
Iodised salt is table salt with potassium iodide added, usually alongside an anti-caking agent so it pours in monsoon weather. The added iodine can carry a faint metallic or slightly bitter edge.
Can you taste it? In a raw, plain, salt-forward context, yes, some people can. Sprinkled on a sliced tomato, stirred into softened butter, in a simple Greek salad where salt is doing most of the flavour work, I can pick it out maybe two times in three. In a stew, a curry, a braise, a bread with yeast flavour in it, nobody on earth is finding it.
The other place it shows up is pickling. Anti-caking agents can cloud a brine and leave a chalky sediment at the bottom of the jar. It doesn’t hurt the pickles, it just looks murky, which is why pickling recipes ask for pure non-iodised salt.
Verdict: buy non-iodised for finishing and pickling if you care about either. For everything cooked, iodised is fine and always has been.
Flaky salt is a texture ingredient, not a seasoning
Maldon-style pyramids and similar hand-harvested flakes are expensive per gram and dissolve instantly. If you stir them into a soup you’ve bought crunch and then destroyed it. That’s the whole argument against cooking with the good stuff.
What they do brilliantly is sit on a surface and pop. The pleasure is the split second where a hard salt crystal hits your tongue before the food does. On warm focaccia, on a fried egg, on a thick slice of tomato, on dark chocolate, on the top of a roast chicken skin after carving.
One rule that has never let me down: flaky salt goes on after the heat is off and after the plate is in front of someone. Add it in the kitchen and it’s already dissolved into the surface moisture by the time the food reaches the table.
A 250 g box lasts me about seven months, and I cook most days.
What “sea salt” on a box actually tells you
That it came from evaporated seawater. That’s it. That’s the whole claim.
It does not tell you the grain size, the density, whether it’s been milled fine or left as flakes, or whether it contains anti-caking agents. Fine sea salt behaves almost exactly like table salt in a measuring spoon. Coarse sea salt behaves more like kosher. Two boxes with the same two words on the front can be twice as different from each other as table salt is from kosher.
Mineral content is the usual selling point. The trace minerals in unrefined sea salt are present in quantities so small that you’d need to eat an implausible amount of salt for them to matter to you in any way, and at that point the salt is your problem, not the minerals. Buy it if you like the texture or the grey colour on a plate. Don’t buy it expecting a different taste in a cooked dish.
Where the cheapest box on the shelf is the right answer
Pasta water. Salting water is the one job where crystal shape is completely irrelevant, because everything dissolves and the only number that matters is grams per litre.
Use about 10 g per litre. A four-litre pot takes 40 g, which is a lot more than most people add and roughly what makes pasta taste seasoned rather than seasoned-on-the-outside-only. It matters most for a sauce that doesn’t carry much salt itself, like a pesto pasta, and slightly less for a salty one like carbonara.
Run the cost. A 750 g box of plain table salt is typically around a dollar, so a 40 g pot costs about five cents. The same pot salted from a 1.36 kg box of kosher salt at roughly six dollars costs about eighteen cents. Not ruinous, but you’ll go through a box a month, and there is no benefit whatsoever on the plate. I keep a cheap box next to the stove purely for water and for the salt that goes into blanching vegetables before a vegetable stir fry.
One plain note, since salt gets discussed a lot in health terms: this is a cooking blog and I’m a home cook, not a doctor or a dietitian. Nothing here is medical or nutritional advice. If you’ve been told to restrict sodium, follow the person who told you, not a recipe.
Picking a winner for each job
Seasoning meat and vegetables by hand: coarse kosher wins, clearly. Big flakes are visible on the surface, so you can see how evenly you’ve covered a chicken thigh, and they’re hard to over-apply because your fingers can only hold so many.
Baking and doughs: fine table salt wins, weighed. It dissolves into a dough evenly and there’s no risk of a stray flake landing in one roll.
Brines and pickles: non-iodised, no anti-caking agents, weighed in grams. Grain size is irrelevant once it’s in solution.
Finishing a plate: flaky, obviously, and only at the last moment.
Boiling water: whatever is cheapest.
If you own one box, make it a coarse kosher salt and keep a scale nearby. If you own two, add cheap fine salt for water and dough. The third box, the flaky one, is a genuine upgrade to plain food and a complete waste of money in anything that gets stirred.