Editor's Note: This ran as an April Fools' article on April 1, 2019.
The annals of cookery are filled with world-changing innovations and discoveries, ones that mark a clear dividing line between the way we used to eat and how we eat for now and forever. The discovery of fire, the creation of the method for transforming grain into bread, the cultivation of wetland grasses into myriad rice varieties—these are but the most basic examples.
In modern times, such changes are rarer but still exist; since the Old World's "discovery" of New World crops, the largest paradigmatic shifts that immediately spring to mind are widespread and affordable refrigeration, Momofuku Ando's creation of instant ramen noodles, Lee Kum Sheung's oyster sauce, and the establishment of the first franchise location of McDonald's.
But there have been relatively minor changes in the way we understand how food is made, and how to make it better, and while a historian with an affectation of using Latin in the course of daily conversation might not be able to point to more widespread use of sous vide technology, for example, and declare "terminus est," the fact that many, many home cooks delight in cooking food in plastic bags dunked into water baths is at least as significant as the fact that it is commonplace to find a device that can irradiate soups, stews, and chicken bakes from Costco in almost every American home.
All of which is to say, today I will offer what I believe to be one of these smaller, world-changing innovations, one similar in kind, but perhaps greater in its implications, to a discovery made by one of my illustrious colleagues here at Serious Eats. I have no doubt that historically minded food bloggers of the future will look back upon the date of May 17, 2016, as one of those moments when the past can be cleaved cleanly from the present, and, of course, I'm sure you all know what I mean. But these are still the dark, ignorant days that follow any great discovery, and some may not know of how their lives have been irrevocably changed.
I speak, of course, of Stella's toasted sugar.
And much as I believe Stella's toasted sugar is a bit of ingenious tinkering, in the same way that great innovators like Steve Jobs stole other people's ideas on his way to becoming a marketing legend, today I have the privilege of offering up my own humble innovation, which just happens to be in every way superior: toasted salt.
Genesis of an Outrageously Brilliant Idea
"Huh? Toasted salt?"
Believe me, I myself asked this very same question of myself when I first asked myself about toasted salt, but "there it is," I said to myself. "A shiny idea," myself replied. The merchandizing possibilities are tremendous [Note to editor: Maybe take this out? It is in my VC prospectus but perhaps inappropriate here?]. But I am getting ahead of myself; first let me tell you how this came to be. As often happens with great discoveries made by dilettantes, it started out as a mistake.
I had run out of my stash of toasted sugar on a winter evening in my trendy Brooklyn townhouse, a prewar colonial brownstone that I was bequeathed in the will of a maiden step-aunt who had inherited a fortune from her grandfather, himself a smoked fish robber baron of the late-early 20th century. So I did what I normally do when I run out of toasted sugar: I fired up my top-of-the-line Swedish-model Wolf stove, dumped four pounds of refined sugar in my enamel-coated copper roasting pan, and babysat it for about four hours, stirring perhaps once or twice an hour with my mother-of-pearl-and-gilt wooden-handled spatula.
I suppose it was when I was admiring my Shun knives that I noticed it, because I looked up and said aloud to an empty room, "My god, I can't smell the sugar," even as the surprise made me momentarily lose manual control of the fine Japanese blade, forged in ancient kilns and folded to the tune of 76 times to produce an edge that is better measured in atom-widths than millimeters, and I cut myself quite badly. But the pain of my finger could not match my delight, nor could the redness of my bright-hot blood blind mine own eyes from the wonder I would behold upon taking my enamel-coated copper roasting pan out of the oven with my Michael Kors oven mitt.
Instead of sugar, I had used the finest Himalayan white salt (rarer and more expensive than the pink variety so popular among Crate and Barrelers). And instead of toasted sugar, I had toasted salt. And when cool, I took a taste simply out of curiosity, dipping my garnet-and-diamond beringed pinky finger into what, for all intents and purposes, looked like plain salt, and knew that I had made history.
What Is Toasted Salt?
The chemically minded out there might scoff at the idea of "toasting" salt. Whereas toasting sugar works by taking advantage of the quirks of thermal decomposition, which you can read about here, no such possibility exists for a substance with the relatively simple molecular structure of salt. But the "toasted" flavor notes of the salt I'd let cook for four hours in a moderately heated oven were undeniable, so I decided to look a little further into what could possibly be occurring.
I conducted a range of experiments using different cooking materials, different varieties of salt, and different cooking times and cooking temperatures. On the low end, I baked batches of salt for one hour at 150°F; on the high end, I baked batches of salt for days at the highest temperatures our test kitchen ovens can achieve, which is 550°F (reliably). I also used my own personal Swedish-model Wolf oven for the higher and lower ends, as it can both go higher and lower and is basically much superior to anything you've ever worked with and costs more than your life.
I will summarize my findings, which were entirely counterintuitive, but I think a visual reference point would be useful. Here then, below, is a batch of fine Himalayan white salt cooked for one hour at 350°F (this was the temperature I eventually ended up discovering was ideal).
And here, below, is that same batch of extremely fine and expensive Himalayan white salt cooked for four hours.
And here, below, is the same batch of superior, extremely fine and expensive Himalayan white salt cooked for 16 hours.
Finally, here is the same batch of excellent, superior, extremely fine and expensive Himalayan white salt cooked for 36 hours.
For ease of reference, I asked our visual director to make a collage of these steps, so you can see more clearly how the fine, really quite-expensive-for-salt Himalayan white salt changes over time (ignore the incorrect labels; they should be, in fact, 1, 4, 16, and 36 [WTF VICKY! I ASKED FOR THIS CHANGE TWO WEEKS AGO! JFC!]).
As is indisputable, something has changed. The question is, of course, "What?"
The Science of Toasted Salt
So if not thermal decomposition, what? If not caramelization, who? If not toasted, then why?
All of these questions, including when, I asked myself. And I believe I have arrived at some speculative conclusions, ones that are nevertheless grounded in some seriously rigorous testing. I believe scientists call this a hypothesis, or theory, like climate change but more grounded in fact.
Let us start with the flavor. It is "toasted," but what does "toasted" mean? You may think of a piece of bread, that has a brown exterior, but has not been browned with the addition of oil or flavorful fat, simply brown because of the way heat interacts with the cut surface of a gluten structure made by killing millions of micro-organisms, so that their sighs as they die can inflate what is otherwise a dense starch matrix. And you'd be right, because that is toast.
Toast takes its flavor from two separate reactions: Caramelization and the Maillard reaction. But since there are obviously no sugars in salt, no matter where you find that salt in the hilly Himalayas, obviously the main culprit must be the Maillard reaction.
As Stella points out about caramelization, scientists similarly have no clue what is happening in the Maillard reaction; in fact, the Maillard reaction is just a blanket term for a bunch of different reactions that occur when food is heated and miraculously, as if Steve Jobs just said it and made it so, like "you're going to think an iPhone is necessary," it becomes tastier. So a natural point of entry to discovering why this salt tasted vaguely reminiscent of toast would be the Maillard reaction.
In the course of my tests, I discovered that there were very distinct differences in flavor, using an oven that can maintain an exact 350°F temperature (like my Swedish-model Wolf oven, which you cannot afford), at the four-hour mark and the 35th-hour mark (this also assumes regular stirring). My working hypothesis is that at the four-hour mark all the latent water that is trapped in the salt is completely evaporated, as the flavor is both salty and kind of dusty, not like the saltiness about your lips after you've been for a swim in the ocean, but the saltiness of using your grandmother's iodized salt shaker filled with little grains of rice (why? really, it has anti-caking stuff already, grandma) on a dry-as-dust chicken breast she prepared for you because you used to love it so much when you didn't know any better.
Between the four-hour mark and the 35th-hour mark there are visual changes, as I pointed out above, but the flavor does not change significantly until hour 35, at which point it takes on deep toasty notes, almost as if the salt crystals are itty-bitty pieces of toast that have each been individually toasted, producing that round, dark bitter note of toastiness that we all love in well-toasted toast.
Keep in mind that this is not like smoked salt, which relies on salt with a relatively high water content in order to trap smoke's flavor. This salt, entirely dried and completely desiccated, has no water to which flavor could bind. But instead, because it is so dry, I believe that what is happening is that the flat surfaces of each individual salt crystal is experiencing one of the many reactions that falls under the umbrella of the Maillard reaction. Think of it like browning cubes of beef for stew; when each of those cubes has just a little bit of browning on it, your stew tastes fantastic. When only half do, it tastes half as fantastic. When none of them do, you're eating at grandma's.
This is why it takes so long, at relatively high temperatures, with frequent stirring, to achieve this toasted flavor in salt.
How to Make Toasted Salt
The process is simple, but I must warn you that if you would like the very best toasted salt, you must start with the very best quality salt. Balinese salt is my current preference, but Himalayan white salt, as I have said, is superb. Kosher salt will work, but Diamond Crystal kosher salt, because of the diamond shape of the crystals, is difficult to toast evenly and will require both more frequent stirring and a longer total cook time.
Do not use Himalayan pink salt, ever.
First, preheat your oven to 350°F.
Next, wash your salt of all impurities. Any random minerality will lead to unwanted bitterness in the final result. Place your salt in a fine mesh strainer, and run water through it until the water runs clear.
Once washed, place your salt in a nonreactive baking dish—glass, anodized aluminum, ceramic, whatever. Put it in the oven and set a timer for 35 hours.
Once every hour, take the salt out and give it a stir, just to ensure even an Maillard reaction.
Remove the salt at 36 hours, and let cool. Once cool, it will keep in a tightly sealed container for five years, but no more.
Once you have your toasted salt in hand, you can use it wherever you would salt. It is good in stews, in braises, or on roasted, seared, or (particularly) cured meats. Sprinkle it over ice cream for a wondrous flavor combination. You can, and I have, eaten it all on its own, straight out of the salt pig.