Week 1: Salt, or, the week of living saltily

We're gonna need a bigger blog.

Salt made sense to me. It seemed natural; salt is simple and everyone uses it, so it should probably be first, right? Right. Bloody well right.

Except, here's the problem. I could easily spend the entire year just talking about salt. Salt is NUTS. (It's delicious on nuts, too!) It's important enough that for most of human history, procuring salt was a primary concern of day-to-day living. But today, we don't really think about salt. We don't have to look for salt licks. We don't need to live by a salt works, and don't need bamboo piping to ship it all over China any more. The idea that there are "salt mines" is more or less a joke, and none of us have ever boiled briny water in pots to extract the salt from it.

That wasn't always the case, though. Three thousand years ago, the Chinese government kept a monopoly on the two most critical substances for day-to-day life - salt and iron. The Romans paid their soldiers in salt.[1] The name the Romans gave to the people we know as the Celts - or Gauls in Latin - means "salt", or "salt people", and rather than the blue-painted, shaggy-haired barbarians that Roman history has handed down to us, they were master salt miners, and had a trade empire that stretched all the way from England to western China, at the time of the birth of Christ. As recently as eighty years ago, a civil rights lawyer named Mohandas Gandhi led a hundred thousand people on a two hundred fifty mile march to commit a heinous act of civil disobedience - to make salt themselves rather than paying the British government's tax on the substance. That simple act eventually lead to Indian independence from England.

As a chemical substance, salt just seems weird. It's the combination of two deadly elements, yet we need it to live. We need salt every day, in fact, in fairly large quantities - but drinking sea water will kill you.[2] It raises the boiling point of water, lowers its freezing point, carries heat so well that it can be used as a cooking medium, and is crucial for making ice cream.

And it's delicious! Not amazing on its own, maybe, but put in on pretty much anything, and woo hoo! When life hands you lemons, break out the tequila and salt!


Let's talk about taste for a minute. Your tongue can pick up five basic tastes - sweet, sour, bitter, savory, and salty. (I know, I know, we were taught four in elementary school. Savory was only added to the list about a hundred years ago, so it's no surprise public schools haven't caught up.) In addition, your tongue can pick up the sensation of spiciness... but then again, so can pretty much every bit of skin on your body, if the spice is potent enough. I mean, your tongue can also sense "getting stabbed" but "stabbed in the tongue" isn't really a taste.

Okay, after doing some science, I've retracted that statement. Stabbed in the tongue is definitely a taste. Kinda coppery.

Now, I want you to make a list in your head of things that taste sweet. Think about chocolate, fruit, splenda, milk, chloroform, lead acetate - all of them taste sweet because they've all got different sugars. Do the same thing for sourness (things with acids in them), bitterness (a huge amount of stuff, much of which needs to be processed to remove toxicity), and savoriness (I have no freaking idea. Savoriness? I was never taught that in grade school.) (Wikipedia says savory taste buds look for foods with high amino acid content... IE, things taste "rich" to us because they're nutrient-dense. Makes sense.)

Now let's look at the list of things that taste salty:

1. Salt

That couldn't possibly be right. To the internet!

Okay. Great Internet has shown me the truth. Here's list 2.0:

1. Salt
2. Potassium Chloride
3. Other cholrides of the alkali metals

So, take a look down the left hand side of the periodic table. First, let's visit #17, chlorine. Got it? Don't hold it too close, though, because it'll turn into hydrochloric acid in your lungs, which is why they used it to clear out trenches in WWI. Now, head all the way to the left, to Sodium, #11. Don't pick it up - you might sweat a bit, and sodium reacts exothermically to water. For those of you without a greek background - gunpowder reacts exothermically to fire. Now, to these two fascinating ways to die, add a little bit of fire, which as I recall is also fairly good at killing folk. Logically, the result should be something that burns you to death, blows you up, then dissolves whatever is left. And yet... (Safety tip - DO NOT try to salt your popcorn by directly mixing sodium and chlorine.)

Now, one of the reasons that the periodic table is so awesome is that it organizes the elements in a fashion that makes them look like they're giving you the fist of metal! Also, they're grouped according to properties - so that potassium, right below sodium, is likely to behave similarly. And, it bonds to chlorine like sodium does, and even has a vaguely salty taste. The problem is that while too much salt will give you high blood pressure, too much potassium chloride will skip the middleman and just kill you. (In far, far higher doses than even the biggest salt fiend would ever use, of course.) As you go father down the periodic table, the stuff that you get becomes less and less like salt, and more and more likely to kill you. So, yes, there's salty tasting stuff out there... but mostly, what we're looking at is salt.


So this is the point that I'm trying to make. Evolution has spent a large amount of real estate in order to detect a single substance - enough that we can readily say that one of the tongue's primary functions is as a salt detector. (You've got to look at what stuff actually does, not just what it claims to do. A book that claims to be an adventure novel exploring the depths that a man will sink to for revenge, but spends half of its pages talking about the minutae of the whale trade, is a book about the minutae of the whale trade.) So I apparently decided that in the first week of my year-long project, I'd explore 1/5th of the tastes that humans can experience. (More than that, if you include "stabbed".) Next week is "all sour things", followed by "bitter delights", after which I will spend forty-nine weeks trying to figure out what the hell savory is.

If there's one thing I'm known for, it's my ability to plan things out. This kind of thing is why.

Still, I've learned a ton of amazing things about salt. Tomorrow: More salt facts, and we make pickles!


[1] Well, probably not. But they did SOMETHING that linked soldiers and salt, though historians are a little bit back-and-forth as to what that actually was. In any case, both the words "salary" and "soldier" have their root in the roman word for salt. Ever thought about what it meant to say someone was worth his salt? (Salad also has the same root.)

[2] Water, water, everywhere, but not a drop to drink: I never understood why this was the case until I started learning about salt; you always read about drinking salt water making you thirstier and thirstier, then killing you. I never believed it. But it's a total head-slapper; obvious once you hear it. Salt is good, yes, but excess salt still needs to be flushed out of your body. The body needs water to do this. The problem is, sea water contains more salt than that volume of water will allow you to clear out of your system. So, you drink your first cup. Your kidneys start doing their job, flushing the excess salt, and you pee, losing water. The problem is, you've used that whole cup of water, but haven't cleared all the salt out yet. Your body wants to pee again, requiring more water. It tells you "Drink more water!" and you do... adding even MORE salt to your over-salinated system. Meanwhile, the extra salt is wreaking havoc on the rest of your system, which uses osmosis to accomplish a lot of basic tasks - dehydrating you. (Didn't you ever wonder why bars are nice enough to server salty snacks, like peanuts and pretzels, for free?) Within hours you start hallucinating, and die really quickly afterwards.

According to Alton Brown, you CAN survive drinking about a .8% salt solution - so if you're stranded on an average-salinity ocean (3.2%) you can stretch your drinking water by adding one part seawater to three parts fresh water.