The taxonomy of salt

I didn't learn much about cooking when growing up. I doubt many boys do - after all, cooking is not exactly a manly activity. I was far too busy engaged in macho pursuits like collecting comic books, or waging 1/80th scale war against Shahram and Yousef in one of our basements. No, I came to cooking fairly recently, which is why I feel like I'm playing catch-up all the time – and why I’m writing this blog.

Prior to a few years ago, when I started to learn how to cook, I might have been intellectually aware that there were different types of salt in existence, but that’s about it. I probably assumed that the kosher salt my mom had was a Jewish thing. (And it is, of course – more on kosher salt later.) And I had seen sea salt as well, smaller and not nearly as flaky as the kosher salt. So, in my head, I figured there were three types of salt – table salt was the smallest, then sea salt, then kosher.

Well, I was partially right – that’s gotta be worth something. What I didn’t realize is that I was looking at one factor about the salt – size – when really, to classify different salts, we need to ask three different questions. First, where does it come from? Second, how big are the crystals? And third, has anything been added to it?

Where does your salt come from?

Go back far enough, and all salt comes from the sea... but we’re really not that interested in where our salt was in the Precambrian era. We’re interested in where the salt was shortly prior to its being packaged. Three options – the sea, a mine, or a refinery. I’m counting the refinery as a separate place, even though the salt that comes out of the refinery came in as either sea salt or mined salt – the thing is, what comes out of the refinery, no matter where it came from originally, is like all other refined salt and unlike the precursor salt that it was refined from. Of course, any salt that gets to your table has been fairly heavily refined; what I’m really referring to when I’m talking about refined salt is the 99.99+% pure mix that winds up in your salt shaker at home.

So what makes refined salt all the same, and other salts, be they rock (mined) or solar (sea) be so different from one another? It’s what the refining process takes out – the impurities. Different salts from different places are going to have vast differences in their precise chemical makeup. (Let me be precise. The salt will be the same no matter where you get it from – it’s 1-2% of “other stuff” mixed into the salt that will be different.)

A quick search for salt merchants will give you some idea of how many different types of salt are commercially manufactured. Every different mine, every different seashore is going to have a slightly different taste; the ones that are unique or exciting-tasting will get a reputation. (Himalayan pink is soooooo hot right now.) Fleur de Sel is the Champagne of salts – hand-harvested from salt pans (evaporating ponds) in a specific region of France. At $2 an ounce, it’s about 25 times as expensive as the kosher salt I’ve got sitting on my table. And since you’re going to have to explain to people that no, this is actually a super rare, expensive salt that you’re putting on their food… I think it counts as showing off. But hey! Maybe I’m wrong, and it does have a sublime taste. I wish this was the “year of having tons of money to spend on gourmet spices.”


How big are the crystals?

I’m going to make this point a few times – these three axes are unrelated to each other. You can have kosher sea salt, for instance – salt from the sea, harvested and processed into large, flaky crystals. Some salts and/or harvesting methods are going to restrict that somewhat – for example, Fleur de Sel has small, delicate crystals; you could make it into Kosher salt by dissolving it and then reforming it, but in doing so you’d be losing what you had wanted to get in the first place.

You can get a good idea of the different sizes of salt available at this site. The salt in their example – the Himalayan Pink (soooooo hot right now!) – goes from less than a millimeter average grain diameter to almost a centimeter. The smallest size would be pickling or popcorn salt – salt that you want to dissolve easily into a brine, or that you want to get caught in nooks and crannies. (If I had it around, I would have used pickling salt for the cashews the other night.) As you go up the line, you get to table salt, then kosher. (which isn’t just larger, it’s harvested so that it’s got a flat, flakier shape) After that, you’ve got pieces of salt that you really need a grinder to take advantage of, and at last proper rock salt. (Which you can still grind, of course. However, this isn’t recommended – rock salt is edible, but is more likely to have nastier-tasting impurities.)



What has been added to it?

There are three reasons to add stuff to salt – public health, marketing, and flavoring.

Every kid in America knows two things about salt: 1. Iodine gets added to it, and 2. This prevents goiters. It’s pretty successful, too – I mean, have you ever even heard of anyone getting a goiter? It doesn’t happen any more, at least in the US – and the cost of iodizing salt works out to about five cents per person per YEAR.

Adding stuff to salt is an incredibly cost-effective way to achieve public health goals. Worldwide, about 66% of people use iodized salt, up from 25% in 1990, when the UN started a push to reduce the worldwide incidence of iodine deficiency. In some places, rather than fiendishly fluoridating the water, the government controls people by putting fluoride in the salt. Devious.

You can also add stuff to salt to make it look better. (Marketing seemed a reasonable thing to call it.) Almost all table salt, and some other salts, will have agents added in prevent it from clumping. They’re generally harmless and minor – but honestly, given the choice, I prefer to leave the sodium silicoaluminate out of my food, thank you very much.

Finally, there’s flavoring. Seasoned salts are pretty popular – I’ll confess to having garlic salt in my pantry – but I’ll defer to Alton here, who points out that such mixes are mostly salt. So, to add a little bit of garlic flavor, you’re adding a lot of salt. Why not just add garlic and salt separately, and put the amount of each that you want on your food? Still, there are some pretty awesome seasoned salts out there.

One neat flavoring device that I’d love to try out is smoked salt. It’s not hard to figure out why it’s called that; after the salt is vacuum dried, it is smoked for a week or so, for the same reason you’d smoke any other kind of foodstuff.

Once again, I want to make it clear that each of these items is totally independent from the others. I don’t think anyone makes iodized kosher salt, but there’s no reason you couldn’t have it. At the same time, you can buy kosher salt with or without clumping agents, etc, etc.


Well, that’s the different varieties of salt. Tomorrow, I’m going to take a closer look at a few of the salts I’ve picked up to cook with, and then maybe, FINALLY, get around to pickling – making Pao Cai, Chinese pickled vegetables.


Addendum: Kosher salt

It’s worth taking a second here to talk about kosher salt. Or maybe to kosher salt.

Yo, kosher salt! Sup wit yo name? I don’t call pickling salt “pickle salt”, why I gots ta call you kosher salt? Yo dang JIZOB is makin’ stuff kosher, but there ain’t nothing kosher about you, because ain’t nothing kosher about ROCKS!

(Of course, if you want religious Jews to buy it, you still need a rabbi to put a stamp on your product saying that yes, it’s salt and not actually small pieces of crystallized pig.)

Okay, so it would be clearer what kosher salt was if it was named properly – koshering salt. Halacha – Jewish law – has a lot to say about how animals should be killed and prepared – and the biggest proscription is against the consumption of blood. The blood is the life, after all. Leviticus 17:10 – “And whatsoever man there be of the house of Israel, or of the strangers who sojourn among you, who eateth any manner of blood, I will even set My face against that soul who eateth blood and will cut him off from among his people.” Consuming blood was an offense which could get you excommunicated – so it was pretty important to get it all out of your food. (The next chapter, Leviticus 18:22, is the bit about man not lying with man as he lieth with a woman… I’ve never understood why that passage is the only one of the hundreds of laws in Leviticus that people who believe that the Bible is the literal word of god ever bother to follow. I think the next time I see someone eating a steak and cursing gays at the same time, I’m going to get my excommunicating stick out.)

Now, take a steak out and throw some table salt on it. What happens? The salt dissolves into the surface of the meat. Try the same thing with kosher salt, and you’ll see something different – the large flakes are too big to simply up and dissolve in the surface moisture. That means that they’ll sit there, being all hygroscopic…y, and suck the liquid out of the meat. The liquid, in this case, being blood. So if it helps, think of kosher salt as tiny little vampires that you’re sprinkling on your food. Maybe it should be called vampire salt!

Kosher salt gets a lot of usage, because it’s easy to handle and generally additive-free. You can pinch a nice amount of it, then spread it where you want, whereas table salt just tends to slip through your fingers and go all over the place. Two things to watch out for when cooking with kosher salt – first, remember, the point of it is that it’s hard to dissolve – so it’s not great for baking (for instance) where you WANT your salt to dissolve nice and evenly. Second, it’s lighter per volume than smaller salts. (This makes sense. Take a big pile of rocks. Fill a bucket with as many rocks as it can hold. Then smash the rocks to sand, and fill the bucket again. The sand bucket will be heavier – it’s the same substance, but the smaller version fills the available space more completely.) So, if you’ve got a recipe that calls for a specific volume of salt, rather than weight, make sure that you note what type of salt it uses. A teaspoon of table salt weighs about six grams, so that’s a good place to start.

Mmmm…. Vampire salt.