This is a transcript of the Gastropod episode, The Colorful Tale of Mexico’s A-maize-ing Grain, first released on July 22, 2025. It is provided as a courtesy and may contain errors.

JORGE GAVIRIA: I remember they had a toaster oven and they had corn tortillas, which felt like very authentic ones. And muenster cheese. And I would just put a piece of muenster cheese on top of a tortilla, put it in the toaster oven and make—basically like toast it until it was like tostada status. With cheese on top, and put some hot sauce on it. And I would have like two of those to start and then I would figure out what I wanted to do after that with my life. That was definitely like my routine and my first sort of, like, conscious relationship with a tortilla.

CYNTHIA GRABER: Chef Jorge Gaviria’s family had fed him tortillas nearly every day before that one, but when he started this routine, this was the time he claimed tortillas for himself. It was an afterschool snack at his grandparents house, but it was also as he says a relationship, the corn tortilla was the thing that helped him feel grounded after he got home from school.

NICOLA TWILLEY: And Jorge is not alone. Millions of people rely on corn tortillas to provide both physical and emotional sustenance every day. Corn is life, for a large part of the world, and corn is also this episode of, yes Gastropod, the podcast that looks at food through the lens of science and history. I’m Nicola Twilley.

GRABER: And I’m Cynthia Graber. This episode we’re telling the story of this essential substance. How did a random grass in what’s now Mexico that had a tiny hard seed head blossom into those impressive stalks with foot-long cobs laden with large starchy kernels?

TWILLEY: And how did that transformation leave corn utterly helpless without its human assistants? Plus, why did those early Mesoamericans get so excited about this almost inedible grain in the first place?

GRABER: How did it become THE food that fueled empires and led to hundreds of different and delicious variations on the all-important tortilla? And what does this all have to do with vampires?

TWILLEY: This episode is supported in part by the Alfred P. Sloan Foundation for the public understanding of science, technology, and economics, and by the Burroughs Wellcome Fund for our coverage of biomedical research. Gastropod is part of the Vox Media Podcast Network, in partnership with Eater.

[MUSIC]

GRABER: One of the things that I always looked forward to in the summer when I was growing up—and honestly I still do today—was and is that first taste of delicious fresh corn on the cob, You know, you slather it in butter, you sprinkle some salt on, you try not to get all the corn bits stuck in your teeth.

TWILLEY: As you listeners know, I grew up in England, where sweetcorn was typically encountered in its revolting canned form. I was a grown adult when I first tried the magic that is fresh corn, shucked, boiled, and buttered, and I was so overwhelmed with its deliciousness that I ate five cobs in a row. Much to my subsequent regret.

GRABER: But what might surprise a lot of you listeners is that sweet corn is not the same thing as the corn used to make tortillas, that’s called field corn.

TWILLEY: They’re in the same family, obviously—they’re all maize.

GAVIRIA: But sweet corn is basically a hundred percent sugar. It’s very sweet. It is meant to be consumed in its, sort of like, fresh state. It doesn’t harden.

GRABER: Jorge Gaviria is the founder and CEO of Masienda, they sell the flour to make tortillas as well as ready-made tortillas and all sorts of other Mexican essentials.

GAVIRIA: So field corn is…it looks, kind of can taste in its raw state, like the Thanksgiving ornaments. You know, that we see on a tablescape? Or you know, hanging from our door. It’s very, very hard. It is, you know, dense. If you were to chew, take a kernel and chew it, it would be—it might crack your teeth, as mine have been cracked over the years, trying that too many times. It is a low moisture, really, really tough kind of pellet in its kernel form. That needs to be cooked down and processed to some degree to make it both palatable and even nutritious.

TWILLEY: Sounds promising. I can totally see why Jorge’s ancestors would have been into this tooth-cracking, hard working grain.

GRABER: If you think that sounds appealing, wait til you hear about corn’s ancestor.

ALBERTO CHASSAIGNE: Let’s go back to the origins and get in the time machine, go back 10,000 years. Our original corn grass is called teosinte.

TWILLEY: Alberto Chassaigne is the man with the time machine. He’s also in charge of the world’s largest collection of corn, it’s based at a nonprofit just outside of Mexico City. It’s called CIMMYT—that’s the acronym for its name in Spanish, which translates to the International Maize and Wheat Improvement Center. When we visited Alberto, he showed us some of this weedy-looking teosinte

TWILLEY: Ohhhh.

CHASSAIGNE: Very hard.

GRABER: And tiny.

CHASSAIGNE: Yes, and tiny.

GRABER: The plant itself gets kind of tall and spindly looking, it’s a bushy tropical grass. And each stalk of grass has these little spikes of grain, like tiny mini cobs covered with small seeds or kernels.

TWILLEY: Teosinte grows wild like a weed all over southern Mexico and Central America to this day. But here’s the thing. For a long time, scientists looking for corn’s origins assumed that maybe teosinte was involved in the mix, but it couldn’t possibly have been the main ancestor. I mean, the wild relatives of wheat actually look like wheat.

GRABER: But teosinte really doesn’t look anything like corn. Those mini cobs are just little long seed heads, really, and they’re covered with a super hard coating, you couldn’t eat those kernels, and when they’re ripe they just burst out and scatter on the ground. You, me, archaeologists in the 70s, none of us would think it was the ancestor of corn.

TWILLEY: And so researchers hunted for the missing link, until advances in science confirmed the impossible: somehow, this unpromising weed was actually *the* source for a crop that Mexico depends on.

CHASSAIGNE: It’s the center of everything. You’ll see if you go to any market, you’ll find corn in almost everything.

GRABER: But not just Mexico, or even just Mexico and other neighboring countries in Central America—globally, more corn is grown than wheat and rice.

TWILLEY: Today, clearly, corn is king. But it was slow off the block compared to the other staples.

DAVID CARBALLO: The process of domestication took a really long time compared to other grains of the world, like rice or wheat.

GRABER: David Carballo is an archaeologist at Boston University, and he told us the first evidence for the domestication of corn comes from about 10,000 years ago.

CARBALLO: It was domesticated in the Balsas River Valley, which is southwest of Mexico City, in the state of Guerrero today.

TWILLEY: Archaeologists have found little plant fossils in caves in that region that are sufficiently different from teosinte to qualify as proto corn. In other words corn that was very early on in its journey to world domination, but corn nonetheless.

GRABER: While I would love to travel in Alberto’s time machine, unfortunately he’s keeping that one to himself, and nobody has figured out a way to ask people what they found appealing in teosinte. But the theory is that before those super small mini cobs ripened and became hard, they were edible, maybe slightly sweet, and the stem was also kind of sugary, so that was something to chew on.

TWILLEY: And possibly to drink. As we know from our ancient beer episode, alcohol is often thought to have been a big motivator for those very first grain farmers.

GRABER: Because they would have chewed on the sugary stalks to get that sugar, then spit the stalks out, and someone might have noticed that the mushy kind of liquidy remains eventually fermented into a kind of corn beer.

CHASSAIGNE: That was a source of calories that was very easy to obtain and very easy to store.

GRABER: And then another theory is that as well as discovering sugar and maybe alcohol, early mesoamericans accidentally discovered a tasty little snack. Here’s how that could have happened: Maybe they were crunching on the stem and maybe this particular teosinte had a slightly larger cob with slightly larger seeds, they were still hard and not particularly edible. But then it fell into the fire.

CHASSAIGNE: And pops like popcorn. So, let’s imagine, back then there was no Netflix, there was nothing, just the stars. There was a campfire. And some teosinte seeds fell into the fire, and they produced pop-teosinte. Not popcorn. And people said, oh, I can bite it and I won’t break my teeth. And I can eat it.

TWILLEY: Still at this point, say something like six to eight thousand years ago, teosinte slash corn 1.0 was a long way from the kind of thing you would happily pick up at the farm stand these days.

CARBALLO: They, they’re these tiny little cobs that we, we really wouldn’t recognize as corn cobs ourselves today. And it takes, you know, many millennia for the, the cob size to increase to something that we would now recognize as corn.

CHASSAIGNE: And from then to that point, about 7,000 more years have passed, and people kept making selections until they had a plant that doesn’t have many stalks, but just one. It had one single large ear, and the seeds didn’t disperse, they stayed put. And so we had our current corn.

GRABER: Part of the reason it took so long to fully domesticate corn is that so many things had to change so much. Like Alberto said, all those tiny cobs on their own individual stalks of grass had to become one cob on one big heavy stalk, the kernels had to lose their super hard seed covering, they had to become bigger and starchier and sweeter, and they had to stay on the cob after they’d become ripe.

TWILLEY: And so in those early years, before corn was finished with this big makeover, it remained just a nice snack and a welcome source of alcohol, rather than the center of the plate. It just wasn’t a staple, for thousands of years.

CARBALLO: That process took a really long time for it to get to a place where people were relying on it as their base subsistence. And it really wasn’t until say, about 2000, or 1500 even BCE, that people started fully committing to being maize agriculturalists and settling down in permanent villages. So the lag between the first sort of experimentation with agriculture. And then becoming full-time sedentary farmers is greater in Mesoamerica than it is in areas like, say, the fertile Crescent of the Near East.

GRABER: David says you can see this change in the bones of the people that lived back then—there’s a chemical signature that shows that maize had become a major part of their diet.

TWILLEY: People had clearly started relying on corn. And somewhere along the line, corn started relying on people.

GRABER: In domesticated corn, the kernels never naturally fall off the cob, and so corn could not survive without humans. It’s our creation, and it needs us to replant it.

TWILLEY: That means it also needs us to spread. And spread it, we did.

CARBALLO: Yeah, corn eventually spread south into the Andes and other parts of South America.

GRABER: In South America, they already had developed and domesticated starchy, high caloric, nutritious foods like quinoa and potatoes and all sorts of other tubers, and so while corn was loved in South America, throughout the Andes region, it wasn’t quite as important. It was eaten but also mostly used for chicha, or corn beer. And they developed corn that looks a little different from most of the corn in Mexico, it has larger kernels.

TWILLEY: Handily for humans, corn proved pretty good at adapting to all kinds of different climates and geographies.

CHASSAIGNE: So the distribution wasn’t just across the continent, but also across the altitudes. And that’s what gives us this great diversity.

GRABER: People selected for the type of corn that they needed, whether it was because of what they wanted to use it for or for the types of growing conditions.

TWILLEY: With our help, corn also moved northward from Mesoamerica to the American Southwest. And eventually to the midwest, too.

CARBALLO: It took a while for this tropical grass species to adapt to this much more temperate, cold winter, different rain regime climate of the Midwest. But once it did, those very rich soils along the Mississippi, Missouri rivers became, you know great corn country. But that, that happens more in the first millennium of our era. So starting around 500 to a thousand or so of the current era. And once that happened, then you start seeing really big urban developments along the Mississippi as well.

TWILLEY: Corn literally fuelled the development of these first big settlements in what’s now the US. For a long time archaeologists couldn’t really explain why the biggest of these Mississippi settlements, a place called Cahokia—why it exploded from a little village to a city of tens of thousands of people almost overnight. It’s only recently they’ve figured it was thanks to corn and all the extra nutrition it provided.

GRABER: We mentioned that archaeologists have used chemical traces in bones to determine when people started eating more corn. And it turns out that around the same time as people started eating more and more corn, they also found a way to make corn more nutritious.

GAVIRIA: The shorthand process is basically cooking that corn in an alkaline water.

TWILLEY: This process is called nixtamalization. And for those of you for whom its been a long time since high school chemistry, alkaline water is at the opposite side of the pH scale from acid, and whereas you’d add lemon to make water acidic, you can add various salts and minerals—for example baking soda—to make it alkaline.

GAVIRIA: You’re just adding a little bit of an alkaline agent in this case, usually, modern day agent would be calcium hydroxide, which is just a basic, high pH substance that helps break down the corn.

GRABER: Calcium hydroxide is also called lime or pickling lime.

GAVIRIA: But, you know, in ancient times, shells, bones, ash, all sorts of sort of alkaline agents were used to kind of experiment to—to do the same thing.

TWILLEY: This relatively simple process of cooking corn in alkaline water is a major win, for lots of reasons. First of all, it loosens the outer shell of the kernel, so that pops off, no sweat.

GAVIRIA: In ancient times, it would kill any pathogens that were occurring, which obviously is really important, because, you don’t want to die from, like, a fungus or you know, a bacteria that might be on that corn if you were trying to eat it and consume it.

TWILLEY: But nixtamalization’s benefits go way beyond getting rid of bad things. It also releases good things.

GAVIRIA: You know, it is turning it into a real nutritional powerhouse. So corn actually has niacin in it. You basically can’t get niacin in corn without unlocking its sort of cell structure and breaking that down. And at that point, when you consume it, it can actually become bioavailable to you.

GRABER: Niacin is also called vitamin B3 and it’s really important to our health and well being. Animal products and other types of whole grains, like wheat, do have B3, but if you’re relying on corn for a major percentage of your calories, getting access to that niacin in the corn is really important. Nixtamalization unlocks that niacin—and it also happens to unlock a couple of other essential amino acids that we have to get in our diet that are in corn but that wouldn’t be available to our bodies without this whole process.

TWILLEY: So nixtamalization was a huge breakthrough for corn and the people of the corn … but we really have no idea who came up with it, or how, or even exactly when. Some of the earliest archaeological evidence that seems to show people were nixtamalizing their corn goes back about three and a half thousand years but it’s a hard thing to pinpoint.

GAVIRIA: Of course, like this was all trial and error and there’s a lot of mystery and also romance that goes into the origin story of this.

GRABER: Because sure it sounds like it was a great discovery, but why would anyone have thought to do this?

CARBALLO: So there’s a debate, exactly what was the impetus for doing this? Part of it could have been. to, you know, make the corn form together better. So you can make things like tortillas.

TWILLEY: Yes, there’s yet another benefit. By breaking down the corn, nixtamalization doesn’t just release essential nutrients—it also releases chemicals that make corn dough softer and stretchier and also tastier. So it’s quite possible the process was originally developed for culinary reasons rather than the health benefits.

GAVIRIA: You know, maybe a pot was out there with ash in it and like you forgot to clean out the ash and you started to cook the corn to break it down, and all of a sudden it started to taste a lot better. It started to taste like umami and I felt much better afterward.

GRABER: However people originally figured it out, nixtamalization was totally transformative.

GAVIRIA: Big benefits are, you know, saving humanity, catalyzing an entire civilization, no big deal.

GRABER: In our recent episode about food and farming in Mexico City before the Spaniards showed up, we talked about how nutritious nixtamalized corn was and is, and how the Aztecs basically could have survived on tortillas and beans with some avocado and veggies and chiles, it was a perfect diet.

JESUS TORNES: That maybe you don’t have meat, that maybe you don’t have fish, that maybe you don’t have like, a poultry.

TORNES: But with corn, with nixtamal, with like some fire and a comal, you’re able to make a tortilla. And you could put like a chili, you could put like a quelite, you could put like a—whatever, and it will be something that will give life to your family.

TWILLEY: This is Jesus Tornes, he’s the co-founder of a corn focused restaurant in Mexico City called Expendio de Maiz.

GRABER: Tortillas weren’t the only way that people used nixtamalization to improve corn. If they left the kernels whole, it’s what we call hominy. This form of nixtamalized corn was originally more common in what’s now northern Mexico and the American southwest, it’s the base of the corn stew called pozole.

TWILLEY: But the point is, nixtamalization was happening. And that was key, if your diet relied on corn. In places that didn’t nixtamalize, there were consequences.

GRABER: We know that because once Europeans encountered corn, they brought it back with them. And it was quickly adopted—not just because it’s delicious, which it is, but because it grows really well on all sorts of land, even not so great land where wheat didn’t grow well. So poorer people who lived on marginal land were able to grow it and harvest a lot more calories for their families.

TWILLEY: Which is why by the late 1700s and into the 1800s, corn formed the basis of a lot of peasant diets in Eastern Europe and Italy, as well as throughout Africa. It provided a lot of calories but there was something missing.

GAVIRIA: They brought back the staple itself, cultivated it, but they didn’t bring back any of the tradition and the wisdom that comes with it. And they, they paid for it dearly with pellagra, which is basically a niacin deficiency.

GRABER: People in the regions that started to rely on corn, they didn’t suffer from pellagra, that’s the medical name for a vitamin B3 deficiency—they didn’t get it before corn showed up. In northern Italy, for example, before corn, polenta just meant grain porridge, it was made with all sorts of grains. But then it became corn porridge, and people ate so much corn polenta—without nixtamalizing that corn—that pellagra became one of the leading causes of death in the region.

TWILLEY: But what’s curious is that this epidemic of pellagra coincided with another epidemic—an epidemic of vampires. The mid-1700s were vampire central in Eastern Europe. It was a real-life mass panic followed by a long tail of folk stories and myths, culminating in the most famous vampire tale of all, Dracula.

GRABER: And guess what, the symptoms of pellagra more than slightly resemble the telltale signs of a vampire. They include skin problems like becoming sensitive to sunlight and developing a corpse-like pallor, as well as insanity and foul breath.

GAVIRIA: The kind of the image we have of vampires, with like really bad skin and kind of like live in the dark because they can’t go outside ’cause they’re too sensitive. That’s largely believed to be the origin of that is, like, just people with niacin deficiencies—pellagra. So let’s have some empathy for vampires out there. They just need a little more niacin.

GRABER: To be fair, this is just one of the theories of where the vampire legends come from. Nobody has proven that outbreaks of pellagra led directly to a vampire story. But pellagra was and is a major problem. It’s still common today in places like Uganda, for instance, that rely heavily on corn without nixtamalizing it.

TWILLEY: So nixtamalization made corn something you could rely on. But, unless you want to eat hominy or pozole at every meal, there’s still work to be done. Next up, how corn kept Mesoamerican women chained to the grindstone for centuries. But—also resulted in some of the most delicious foods known to humanity. But first, a quick word from our sponsors

[BREAK]

TWILLEY: So after you’d harvested corn and dried it and got it off the cob, you’d boil it with alkaline water, as per. But from there, dealing with corn becomes a total grind. Literally.

ROXANA LARRONDO: Once this process was over, we would pass it to the metate and then we would grind it.

GRABER: Roxana Larrondo does outreach for the Herdez Foundation of Mexican gastronomy. We described the metate in our recent episode, when the folks there used it to grind tortillas for atole. It looks like a large mortar and pestle made from porous volcanic rock. Using it is a lot of work.

LARRONDO: For it to be 100% ground, a woman had to pass it up to seven times on the metate. Which is quite tiring. So, tiring for your knees, tiring for your back, and tiring your arms.

TWILLEY: This task was backbreaking. From a young age, Mexican women spent most of their time kneeling on the ground grinding corn. Anthropologists estimate that traditionally, Mexican women spent five or six hours turning corn into tortillas, every single day. They couldn’t even get ahead and make two day’s worth in one go because—yes, you guessed it, my favorite topic, refrigeration!—without it, tortilla dough couldn’t be kept overnight without fermenting.

GRABER: The next part of the process, making the tortilla, that didn’t take nearly as much time. Women would shape small, wet balls of tortilla dough, or masa, in their hands, flatten them out, and then cook them quickly on the hot flat comal. But this also took a lot of knowledge: how wet the dough should be and how thick, how long it should cook on the comal.

GAVIRIA: It was something that was sort of a rite of passage. As you became, you know, a young woman, you were expected to learn how to make masa, make tortillas. And that’s where that kind of myth comes from. If you get a tortilla to puff, it means you’re ready to marry.

GRABER: My partner Tim can in fact now get a tortilla to puff, which is good because we’re already married.

TWILLEY: Roxana told us that the puff, that’s a key part of the anatomy of a perfect tortilla.

LARRONDO: The thick part is called the loin. And what inflates when you put it on the comal, is called the belly. The tortillas here functioned as food, as a plate, as a spoon, and also as a napkin. They would divide the belly from the loin. And they would wipe the corner of their lips. And that was what served as a napkin.

GRABER: Different parts of the tortilla served a lot of different purposes, and the tortilla itself, well, it was the basis for a LOT of different dishes.

CHASSAIGNE: There’s a lot of talk about vitamin T here. After you have dough, you can make a tortilla—and all the products from Mexico that also come from tortillas. Don’t tell Mexicans, but everything is a tortilla. The tortilla is very, very practical because it turns into whatever you want.

GAVIRIA: You can take that tortilla and fold it into, like, a triangle, which sort of resembles a crepe. And it’s a tetela. You can shape it into like, a football, oval-looking thing, which is a tlacoyo, kind of the original Hot Pocket. You can make a huge version of it, and call it a tlayuda, which needs to be like a certain level of crispness. Totopos, which are you know, basically tortilla chips and been cut from a tortilla. I mean, it’s just a—it goes on and on. And there’s so many different, also like regional variations on what we name these things, as you can probably imagine. But I think, I think like a couple dozen core shapes and then lots of different names to confuse people in between.

TWILLEY: There may be a zillion different names for things made from masa, but there’s also lots of different names for corn itself.

CARBALLO: Just like apparently people in the Arctic have many words for snow, people in Mexico have many words for maize. The term for—we would just say cob, but if, if it is a cob that has kernels on it versus a cob that has no kernels on it, those are two different terms. And so you get this sort of elaboration of, of terminology. Or whether it’s young corn versus older corn, or it’s been shucked, those are all like, all different terms.

GRABER: And all of this—the names for corn, the names of corn-based dishes—all of this makes it pretty clear that corn was THE center of the world in Mesoamerica.

GAVIRIA: I mean, corn is life. It is like, there’s, there’s very, little separation, if any, between, you know, literally the life that we have and corn itself. We are inextricably linked. You know, we come from corn, and corn comes from us.

TWILLEY: David told us this belief goes deep. It’s echoed in all sorts of different origin stories from the region.

CARBALLO: The maize god is very big in Maya art and religion. There are these origin stories of these, these twins who, you know, do all these feats and defeat bad gods. And then their father is the maize god, and they sort of rejuvenate him.

GRABER: David said that corn isn’t quite as obviously prominent among Aztec gods, but one of the most famous Aztec gods, Quetzalcoatl, he’s seen as bringing maize to the people.

CARBALLO: And so there’s, you know, different tellings of whether he went down into the underworld and brought back maize, or he sent an ant who went down into the underworld and brought back maize. But it is certainly part of the narratives of creation within the Aztec world as well.

TWILLEY: Because corn is more than just food, different corn dishes have become associated with different rituals.

TORNES: So making pozole for us is a ritual for—I’m going to give you an example. If someone get married, you’re going to make pozole. If someone died, you’re going to make pozole. If this birth of someone, you’re going to make pozole.

GRABER: And then different varieties of corn have been selected for those rituals and special occasions as well.

GAVIRIA: So like red corn, blue corn. A lot of these were really, celebration kind of based occasions where you would use it. A birthday or a wedding or something. Some kind of ceremonial kind of experience. But, very special and so not used as often.

TWILLEY: Corn cross-pollinates easily—that’s what makes it so adaptable, but it also means that you end up with lots of different varieties with lots of different colors and shapes and sizes and textures. And people would choose the ones they wanted to keep and grow based in part on what they were going to use it for.

TORNES: When you understand that every race of corn, it’s related to the selection of a lady of the next grains or the next seeds for the next year. And this happen every year, through thousand of years. So: you go with each family and let’s think that one family make tortillas. So this family, it will be more important to select the corn for making tortillas. If there’s someone who make tamales in this community, they will produce their corn selecting, every year, the seed for having like a better corn quality for tamales. Let’s think that you’re going to make pozole so you’re going to select like the fat corn we call anchos. So the most important thing for every person will be different.

TWILLEY: A lot of these differences are to do with the starch content versus the stretchiness of the masa, which gives it different culinary qualities.

GRABER: And Jorge and Alberto told us that when it comes to the colors of the corn, it’s not just a visual thing. They taste different too—it’s subtle but there are variations.

GAVIRIA: Typically for white, they tend to be pretty creamy, you know, have like a bit of a, a popcorn flavor to it, honestly. Yellow has some of the highest oil content of the varietals that we work with. So the, kind of the flavor lingers on your palate more. They’re just cornier, for lack of a better description? Like, whatever you imagine corn tasting like, amplifying it by like 10 times. And red and blue can kind of vary between like grassy and nutty notes to a little bit sweeter.

CHASSAIGNE: Connoisseurs, when they try a blue tortilla, immediately recognize that it has a very special flavor compared to a white one.

TWILLEY: Okay, I know a challenge when I hear one. Can Cynthia, connoisseur of all things including corn, taste the difference between different color tortillas? Fortunately, I had an opportunity to put her to the test when we went to Maizajo, a restaurant in Mexico City that prides itself on its diverse corn menu.

GRABER: So there’s maíz azul, maíz amarillo, maíz rojo y negrito, blanco.

GRABER: That was the list of some of the different varieties of corn they work with, but when it came to the tortilla chips on the table, we had two varieties, a blue and a yellow.

GRABER: I feel like I need to close my eyes and see if I can…

TWILLEY: Yeah, you want me to give you?

GRABER: Yeah, give me one of each. My eyes are closed.

TWILLEY: As instructed, I handed Cynthia one of each of the chips.

GRABER: Okay. Okay, so I’m putting one in my mouth. [CRUNCHING]

GRABER: I tasted each one once.

GRABER: Taste delicious like corn, nice and crispy, a little like hint of the smoke from the comal.

GRABER: I was pretty sure I knew which was which, but I went and tasted the first one again just to make sure.

GRABER: That one, this one that I’m eating tastes more popcorny? I’m going to guess it’s the yellow.

TWILLEY: Correct. You are correct. And you have won our grand prize of yet more corn. But yeah, first one was yellow, second one was blue. I’m impressed.

GRABER: I have to admit, I’m pretty proud of myself. I am apparently indeed a corn connoisseur.

TWILLEY: Once Cynthia aced the chip test, we both got stuck into some serious vitamin T.

GRABER: We have a very pretty memela, which is a thick oval… tortilla. We have a tetela, which is a triangular tortilla. Like, folded around stuff. And then we have a quesadilla, which is a thin tortilla that’s folded together and cooked that way. And a little tostada, which is a crunchy one with stuff on it. This, in this case fish.

TWILLEY: Cynthia, what we have here is corn. Corn four ways.

GRABER: They were truly delicious. It was also probably the most different varieties of vitamin T I’ve had at one meal, and I’d happily do it again.

TWILLEY: And until not so long ago, if you lived in Mesoamerica, that’s exactly what you would have done, with breaks in between to grind masa for hours on end, because you’re a woman—sorry. Corn culture, corn cuisine, corn traditions: they were all alive and almost unchanged until quite recently.

GRABER: The story of how industrialization freed women but also nearly broke corn—and how corn is being saved, after the break.

[BREAK]

TWILLEY: One thing you might be wondering is why on Earth so many Mexican women were chained to the grindstone for so long, when in the rest of the world, going back thousands of years, there were mills where people could get their grains ground by a horse-drawn or water wheel-turned millstone.

GRABER: Turns out that this technology just didn’t work for nixtamalized corn. Sure, in theory you could have been grinding hard dry corn in a mechanical mill, but then it wasn’t nixtamalized and you might get pellagra. If, on the other hand, you cooked and soaked the corn in lime, it was too wet for a mechanical mill. People tried, but it didn’t work well, and the texture of the masa was all wrong. It took a while for anyone to get it right.

TWILLEY: In fact, it wasn’t till the mid 1800s, that people finally figured out how to make a mechanical mill that could grind masa without getting gummed up *and* get it fine enough to make a good tortilla.

GAVIRIA: It’s happening first in urban centers, through the mechanization process. And then that would start to kind of extend into more rural areas where in the center of town you would have a mill or a molino where the matriarch would go bring their corn that they nixtamalized, you know, at the crack of dawn so they could have it for breakfast, lunch, and dinner.

GRABER: That was step one. Step two was coming up with a mechanical tortilla press. This was hard, too, again because the dough is so sticky, and getting the thickness of the tortilla just right *and* keeping it from sticking to the press also took a couple of decades to develop.

TWILLEY: And then step 3, which really revolutionized the world of corn: dried masa flour. It was perfected in Texas in 1908. All of this together meant that women, or at least some women, were finally free from making masa to feed their family every single day. Dried masa—the biggest brand today is Maseca—for the win.

GRABER: Compared to the whole business of drying and nixtamlizing and grinding, dried masa is like magic.

GAVIRIA: It’s really, really thrilling to just add water to something and shape it and cook it into a tortilla.

GRABER: Jorge grew up eating tortillas but he hadn’t made them himself until he was working as a chef in a taqueria in New York. It kind of blew his mind.

GAVIRIA: I was like, oh my gosh. This is like the true, authentic way to make a tortilla. It’s just adding water to this powder that I have no idea, like how it’s made. And, you know, shaping it and then cooking it and then I have a tortilla.

TWILLEY: It wasn’t till later that Jorge realized, hold on: this is like Folgers. This is not the tortilla of myth and tradition. Tortillas made with industrial dried masa are soft, and reliable, and a lot less work for the woman of the house, but they’re not the tortilla of his ancestors.

GRABER: And not just because it didn’t take quite as much labor. It’s also because the corn itself is different. Since the mid 1900s, most of the corn grown and nixtamalized and dried and used in tortillas is industrial corn.

GAVIRIA: The raw corn that they’re using is… it’s certainly bred for just yield and, you know, commercial considerations and not so much the flavor.

TWILLEY: But all is not completely lost. Despite the rise of industrial corn and Maseca, both Alberto and Jorge told us that a lot of smallholder farmers in Mexico still grow traditional varieties.

GAVIRIA: These are kind of like the custodians of what is essentially like the largest open seed bank in the world for corn. And these are varietals that are literally just preserved from one year to the next because they taste really good. They’re selected each year because they look beautiful. They taste amazing. They’re not the most efficient things to grow, but like what a romantic thing, that they’ve—they’ve stood the test of time because of how much pleasure they give the person who’s growing them and, and creating masa from them.

TWILLEY: Romantic, delicious, but also increasingly endangered.

CHASSAIGNE: What we see is a significant loss—a significant loss of diversity.

GRABER: There are a lot of reasons for that loss of diversity. Industrial corn is a lot cheaper and more efficient to grow, and that makes it hard for smaller farmers to compete. These small scale Mexican farmers were also hammered by trade agreements with America, because industrial corn grown at scale in America is even cheaper. And those agreements let us flood the Mexican market with cheap corn.

CHASSAIGNE: And we went from everyone having their own variety and being very proud of it, to going to a supermarket and buying flour. Or going to the corner where they can get the tortillas already made. There’s no time to grind them, much less to plant and harvest corn. My current concern is, before, people were very proud to say that they’re farmers. You had plants passed down from your grandfather, your great grandfather. Nowadays, the kid who’s living in the countryside wants to leave. He wants the advantages that cities offer. In Mexico, he could go to North America to fulfill his dreams.

GRABER: And so some people stopped growing their local varietals. That’s not what goes into Maseca, so that means it’s not what goes into almost all tortillas.

GAVIRIA: And these were largely folks who were doing it on a subsistence level. And so if they found that there was no incentive to do that for themselves, they weren’t going to do it for anybody.

TWILLEY: And what that means is that the incredible diversity of corn—the purple corn, and the corn with the cobs that are 2 feet long, and the corn that’s so productive it’s named after a rabbit—all these corn varieties developed over millennia, they’re under threat.

GRABER: Luckily both Jorge and Alberto are working to keep all those varieties of corn from disappearing and save them for the future.

CHASSAIGNE: Ready? Let’s go to the cold.

GRABER: Perfect.

TWILLEY: Okay. Yeah.

[LOCKPAD BEEPING]

[VAULT OPENING]

CHASSAIGNE: Whoosh! Welcome to Disneyland.

TWILLEY: We had put on thick jackets to visit this particular Disneyland of corn, because it was about minus 2 degrees celsius which is just 28 Fahrenheit. Alberto told us that the plan is to bring it down to below zero Fahrenheit.

CHASSAIGNE: So you’re lucky because you’re going to be one of the few who’ve been able to get in here. When it reaches about minus 18, we won’t be able to host visitors.

GRABER: I wasn’t too cold at 28 degrees—I live in Boston, so that’s not a huge deal—but below zero? Yeah, that’d be a bit much.

TWILLEY: As readers of my book will know, refrigeration works by slowing down how fast fruit and vegetables breathe. The same thing was happening to all the corn kernels stored in this chilly vault. Lots of them were also tightly wrapped against the air.

CHASSAIGNE: We’re using triple-layer aluminum packaging, vacuum-sealed. Because the seed is a living being, and it’s breathing. The more oxygen we give it, the more it’ll breathe.

GRABER: It was kind of amazing being surrounded by almost 30,000 different varieties of corn from 81 different countries. Not all of it was wrapped up, so we could see kernels of different sizes and colors—some were black or purple, some were like large buttons. There were varieties that grew in all sorts of different landscapes, it really was a universe of corn.

TWILLEY: Like we said, this is the world’s largest collection of corn, and Alberto is the man responsible for it. It’s a genebank: a way to make sure that the unique DNA from those 28000 plus varieties is preserved for the future. The collection at CIMMYT got started in the 1940s and its mission is to collect, preserve, distribute, and improve corn.

CHASSAIGNE: Yes, it’s a titanic task, a huge responsibility. Fortunately, for many years, we’ve had financial support for these facilities because it is very, very, *very* expensive.

GRABER: The first major cost is keeping everything so cold.

CHASSAIGNE: That means constant electricity. That means a lot of money.

TWILLEY: And even deep frozen, sure, the seed will be okay for decades, but it can’t survive forever. Alberto told us he has to keep a constant eye on his corn because it has to be refreshed every so often. Which is a major performance, because remember that corn cross-pollinates really easily.

CHASSAIGNE: When you plant a lot of different things in the field, you have to prevent the pollen from mixing between varieties. So you have to help out fertilization.

GRABER: It’s a lot of work. So why go through all of this expense and bother?

CHASSAIGNE: So, let’s say that within the 28,000 that we have, there are some that would be very useful because they’re resistant to a corn disease. Or they might be able to tolerate a drought, or another environmental condition. These powers would be in our superhero, in our Captain America—we have our Captain America frozen, sleeping for 50 years.

TWILLEY: This is not just a theoretical superhero corn-saving-the-day situation. Alberto told us that corn from the CIMMYT collection has already come to the rescue against a nasty corn disease called Tar Spot, which can easily take out a quarter of your harvest.

CHASSAIGNE: It’s deadly for corn. And research was done here at the germplasm bank. They had corn from Guatemala and from Oaxaca that had resistance to the disease. So, from there, they moved on to the genetic improvement program. They developed hybrids. And of course that’s been publicly distributed, and companies are already starting to use that corn. But that’s a very concrete example. We’re talking about something that was here, sleeping and protected—our superhero.

GRABER: Alberto and his colleagues do extensive research and breeding at CIMMYT. In fact, around 50 to 70 percent of all the corn grown in the world can be traced back to breeding programs there.

TWILLEY: But they also provide original samples from their collection. Last year, they sent more than 4,000 samples out to people in more than 100 countries.

CHASSAIGNE: It could be a university that wants to do a characterization. It could be a company that says, “I’m going to use it directly, to create an improved variety.” Or it could be a high school teacher who wants to make a garden and show the students. We get everything.

TWILLEY: Anyone can request corn and CIMMYT will send it out to them.

CHASSAIGNE: Yes. It’s key. I don’t want a morgue. I want something that’s useful.

GRABER: But CIMMYT doesn’t have everything they want when it comes to corn. They don’t have every variety of corn in the world. And they also don’t know every detail about the corn they do have.

CHASSAIGNE: People want me to tell them what corn is useful—for this region of Iowa, that is resistant to diseases, that yields a lot, and that works against dandruff. We don’t have all that information. I wish we did. For example, we would love to study and understand the nutritional quality.

TWILLEY: But that would take going through the DNA of every sample and then growing each variety out and correlating its qualities with the DNA—it’s a huge project.

CHASSAIGNE: What externally looks the same—being able to study the DNA could tell us that one is tolerant to drought, the other could be tolerant to heat. That’s what gives added value to a germplasm bank —knowing what it’s useful for.

GRABER: This have some of that data, but not all—not yet. Still, what they’ve accomplished at CIMMYT is essential for corn, and Alberto is proud of what they’ve done and what they’ll continue to do in the future. But he says at the end of the day the survival of corn also depends on the survival of farmers.

TWILLEY: Because while the corn in Alberto’s collection might be preserved in the cold, without farmers growing those varieties, the corn will stop adapting and diversifying. And then it’s almost as good as dead anyway.

CHASSAIGNE: We’re not going to have anywhere to go to get that new diversity. And it’s very worrying. That’s the big concern right now. If diversity depends on what’s kept in the countryside, and we don’t keep youth in the countryside, forget about a future for the native breed.

GRABER: That’s just the side of the problem that Jorge is working on. Supporting the farmer in Mexico, growing all those varieties of multicolor native corn, is what his business Masienda is built around.

TWILLEY: Jorge started out just wanting to make a great tortilla.

GAVIRIA: I was going to start a tortilleria. Like a tortilla bakery basically. I was going to kind of model it in the, the image of Tartine Bakery. I was like, we’re going to do the same thing that Tartine did for, you know, country loaves, we’re going to do the same thing for tortillas. It’s going to be this magical process to watch.

GRABER: But then he started to think about what tortillas are made from—you know, corn.

GAVIRIA: Long story short, I started just thinking about like, well where does corn come from? You know, where does this foodway start? And the answer is, Mexico. It was born in Mexico, invented in Mexico. There’s still this unbelievable kind of living, seed bank.

TWILLEY: Great but Jorge immediately noticed that ,like we said, this unbelievable living seed bank was under threat. Smallholders were still growing some of these varieties for themselves, but as older generations passed on, their kids weren’t necessarily taking over. There just wasn’t a living to be made growing these traditional heirloom corn varieties

GAVIRIA: And so the experiment was to try to create a market for it. And basically just paying fair retail prices for wholesale quantities of varietals that were being grown by these subsistence farmers. And we started with 12 farmers you know, back in 2014.

GRABER: At that point, Jorge’s business plan was to produce masa flour from all this delicious corn and sell it to restaurants and home chefs. But he wasn’t sure it would take off—he kept his day job at Dan Barber’s restaurant in New York.

GAVIRIA: I was still working at Blue Hill and taking calls from the customs broker in the bathroom during service. People were like, where is Jorge at? And I would be, like, in the bathroom for 30 minutes, just like cleaning the bathroom. But talking to a customs broker, because I needed to get the corn across the border.

TWILLEY: He was wrangling logistics, and he was also having to convince smallholder farmers he was for real.

GAVIRIA: What was funny to me is that we were really excited when I saw—I remember seeing a red conico, which is one of the varietals that we use for our red masa flour. And when I asked the farmer, his name was Armando, I said: do you, you know, like, how much do you want for this?

GRABER: The farmer was like, what, you want to buy this? It’s just something we grow for ourselves. It’s nothing special.

GAVIRIA: We were just like, what are you talking about? Like, this is so delicious. Like it has like a nutty quality to it. It’s just like, dare I say, it like tastes like slightly sweeter

TWILLEY: It took a lot of work, but in the end, Jorge got out of the toilet, quit his day job, and he told us Masienda is now having a real impact keeping corn farmers and their heirloom varieties alive while bringing more deliciousness to our plates.

GAVIRIA: So we work, like I said, about 2000 smallholder farmers in Mexico. And in terms of total varietals, I mean, probably, 20, I would say?

GRABER: Today, Masienda sells four colors of masa flour, and with those and a tortilla press that they also sell you can make truly, kind of shockingly soft and delicious tortillas at home if you’re so inclined. They also sell ready made tortillas and frozen quesadillas, and they’ve expanded to other Mexican products like fantastic dried beans and even edible ants.

TWILLEY: Jorge’s is just one effort to create the conditions to keep these varieties alive. But the impact goes way beyond the plate. Because even though Alberto is proud of taking care of the world’s largest collection of corn, like we said, he knows that if it isn’t being grown, it will stop adapting.

GRABER: And corn has a lot of adapting to do. Or at least the humans who grow and breed corn have a lot of work ahead to help it adapt. Because Alberto told us that researchers project that by 2080, corn harvests are going to be cut in half by climate change.

CHASSAIGNE: So, in a projection of a Mexico with Sinaloa producing less corn, it’s going to be a total crisis at the tortilla level. Because Sinaloa, Jalisco and Bajío are the regions producing the corn that feeds more than 50 percent of the national production. So, if we already know that we are going to have a problem in the future, then we have to find the solution today. Using the germplasm of yesterday.

GRABER: And that solution can be found both in the vault and on the field—it’s in the living biodiversity of this ancient grain.

GAVIRIA: The more diverse anything is, any population is, the more vibrant it is, the more interesting it is, the more healthy it is from a lot of perspectives. Biodiversity tastes better. It looks better. It is… it’s more interesting and it is just overall healthier.

[MUSIC]

TWILLEY: We know, we know, there’s so much more to say about corn. We made a whole episode without even mentioning corn syrup! But fear not, we plan a corn comeback in the future. You’ll just have to keep listening. And you know, supporting us, so we can keep making the show.

GRABER: Thanks this episode to Alberto Chassaigne, Jorge Gaviria, David Carballo, Jesus Tornes, and the folks at the Herdez Museum, we have links to their organizations, research, and restaurants at gastropod.com. Thanks also to the fabulous Rodrigo Perez Ortega, he’s a science journalist in Mexico City, and he helped us make this trip a reality.

TWILLEY: I also want to thank Rachel Laudan, a wonderful food writer who was the first to impress upon me exactly how backbreaking the daily task of grinding corn would have been.

GRABER: Thanks as always to our fantastic producer Claudia Geib. And a final thanks to the folks who did our voice-overs: Maria Monica Ruiz and Andres Paramo. We’ll be back in two weeks. Till then!