The Colorful Tale of Mexico's A-maize-ing Grain

0:03I remember they had a toaster oven and they had corn tortillas which felt like very authentic ones and munster cheese. And I would just put a piece of munster 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. 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.

0:46It was an after-school 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. 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. 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?

1:29And how did that transformation leave corn utterly helpless without its human assistance? Plus, why did those early Mesoamericans get so excited about this almost inedible grain in the first place? 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 all of this have to do with vampires? This episode is supported in part by the Alfred P. Sloan Foundation for the Public Understanding of Science, Technology, and Economics, and by the Burr's Welcome Fund for our coverage of biomedical research. Gastropod is part of the Fox Media Podcast Network in partnership with Eater.

2:32are back at Starbucks. The one and only pumpkin spice latte and the deliciously smooth iced pecan crunch latte have arrived and are ready to sip all season long. Or find a new favorite, like the new iced banana bread latte that tastes just like fall in a cup. You can find your favorite taste of fall only at Starbucks. One of the things I always look 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.

3:10As you listeners know, I grew up in England where sweet corn 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. 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. They're in the same family, obviously. They're all maize. But sweet corn is basically 100 % sugar. It's very sweet. It is meant to be consumed in sort of like a fresh state.

3:47It doesn't harden. 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. 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 dense. If you were to take a kernel and chew it, 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 process to some degree to make it both palatable and even nutritious.

4:30Sounds promising. I can totally see why Jorge's ancestors would have been into this tooth-cracking, hard-worked grain. If you think that sounds appealing, wait till you hear about corn's ancestor. Let's go back to the origins and getting the time machine. Go back 10 ,000 years. Our original corn grass is called Teosinte. Alberto Chesaine 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 non-profit just outside of Mexico City. It's called CIMIT. That's the acronym for its name in Spanish, which translates to the International Maize and Wheat Improvement Center.

5:10When we visited Alberto, he showed us some of this weedy-looking teocente. Very hard. And tiny. Yes, and tiny. 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. Teocente 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 Teocente 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.

5:52But Teosinte really doesn't look anything like corn. Those mini cubs 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. 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. It's the center of everything. You'll see if you go to any market, you'll find corn in almost everything.

6:32But not just Mexico, or even just Mexico and other neighboring countries in Central America. Globally, more corn is grown than wheat and rice. Today, clearly, corn is king. But it was slow off the block compared to the other staples. The process of domestication took a really long time compared to other grains of the world like rice or wheat. 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. It was domesticated in the Balsas River Valley, which is southwest of Mexico City in the state of Guerrero today.

7:09Archaeologists 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. While I would love to travel in Alberto's time machine, unfortunately he's keeping that one to himself, and nobody's 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.

7:45And 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. Because they would have chewed on the sugary stalks to get that sugar and 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. That was a source of calories that was very easy to obtain and very easy to store. And then another theory is that as well as discovering sugar and maybe alcohol, early Mesoamericans accidentally discovered a tasty little snack.

8:20Here's how that could have happened. Maybe they were crunching on the stem, and maybe this particular teocente had a slightly larger cob with slightly larger seeds. They were still hard and not particularly edible. But then it fell into the fire. Y revienta como popcorn. 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 teocente seeds fell into the fire, and they produced pop teocente, not popcorn. and people said, oh, I can bite it and I won't break my teeth and I can eat it. Still, at this point, say something like 6 ,000 to 8 ,000 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.

9:10There are these tiny little cobs that we really wouldn't recognize as corn cobs ourselves today. And it takes, you know, many millennia for the cob size to increase to something that we would now recognize as corn. 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 stocks 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. 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.

10:01The 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. 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. Just wasn't a staple for thousands of years. 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.

10:44So 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. 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. People had clearly started relying on corn, and somewhere along the line, corn started relying on people. In domesticated corn, the kernels never naturally fall off the cob, and so corn could not survive without humans.

11:18It's our creation, and it needs us to replant it. That also means it needs us to spread, and spread it we did. Yeah, corn eventually spread south into the Andes and other parts of South America. 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.

11:51It has larger kernels. Handily for humans, corn proved pretty good at adapting to all kinds of different climates and geographies. So the distribution wasn't just across the continent, but also across the altitudes. And that's what gives us this great diversity. 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. With our help, corn also moved northward from Mesoamerica to the American Southwest and eventually to the Midwest, too. 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.

12:35But once it did, those very rich soils along the Mississippi, Missouri rivers became great corn country. But that happens more in the first millennium of our era. So starting around 500 to 1 ,000 or so of the current era. And once that happened, then you start seeing really big urban developments along the Mississippi as well. Corn literally fueled the development of these first big settlements in what's now the U.S. 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.

13:16It's only recently they figured out it was thanks to corn and all the extra nutrition it provided. 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. This shorthand process is basically cooking that corn in an alkaline water. This process is called nixtamalization. And for those of you for whom it's been a long time since high school chemistry, alkaline water is at the opposite side of the pH scale from acid.

13:50And whereas you'd add lemon to make water acidic, you can add various salts and minerals, for example, baking soda, to make it alkaline. 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. Calcium hydroxide is also called lime or pickling lime. But, you know, in ancient times, shells, bones, ash, all sorts of sort of alkaline agents were used to kind of experiment to do the same thing. This relatively simple process of cooking corn in alkaline water is a major win for lots of reasons.

14:32First of all, it loosens the outer shell of the kernel. So that pops off. No sweat. 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, bacteria that might be on that corn if you were trying to eat it and consume it. But nixtamalization's benefits go way beyond getting rid of bad things. It also releases good things. 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.

15:11And at that point, when you consume it, it can actually become bioavailable to you. 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.

15:43So 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. 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. Because sure, it sounds like it was a great discovery, but why would anyone have thought to do this? There's a debate exactly what was the impetus for doing this.

16:19Part of it could have been to make the corn form together better so you could make things like tortillas. 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. Maybe a pot was out there with ash in it, and 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.

16:55It started to taste like umami, and I felt much better afterward. However people originally figured it out, nixtamalization was totally transformative. Big benefits are saving humanity, catalyzing an entire civilization. No big deal. 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 avocados and veggies and chiles. It was a perfect diet. That maybe you don't have meat, that maybe you don't have fish, that maybe you don't have like a poultry.

17:31But with corn, with nixtamal, with like some fire and a comal, you're able to make a tortilla and you could put like a chile, you could put like a quelite, you could put like a whatever. whatever, and it will be something that will give life to your family. This is Jesus Tournez. He's the co-founder of a corn-focused restaurant in Mexico City called Expendio de Maíz. Tortillas weren't the only way that people use 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.

18:03It's the base of the corn stew called pozole. 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. 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. 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.

18:45It provided a lot of calories, but there was something missing. They brought back the staple itself, cultivated it, but they didn't bring back any of the tradition and the wisdom that comes with that. And they paid for it dearly with pellagra, which is basically a niacin deficiency. 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.

19:22But 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 tale of folk stories and myths, culminating in the most famous vampire tale of all, Dracula. 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. 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 because they're too sensitive.

20:06That'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. To be fair, this is just one of the theories of where the vampire legends come from. Nobody's 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. 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.

20:42Next 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. Fall is here, and that means the pumpkin spice latte is back at Starbucks. It's the one we've been waiting for. So whether you're a fan of the original pumpkin spice latte, or ready to mix it up with an iced pumpkin cream chai, the new iced pumpkin cream matcha, or the new iced pumpkin cream shaken espresso. You can find your favorite taste of fall only at Starbucks. Fall is here, and that means the pumpkin spice latte is back at Starbucks.

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21:58And turn that I wish we could into an I'm so glad we did. Visit Amazon.com slash Prime to find millions of items delivered fast. Same-day delivery. It's on Prime. Available in select areas. Terms apply. 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. Once this process was over, we would pass it to the metate and then we would grind it. Roxana Lorando does outreach for the Herdes Foundation of Mexican Gastronomy. We described the metate in our recent episode when the folks there used it to grind tortillas for atole.

22:44It looks like a large mortar and pestle made from porous volcanic rock. Using it is a lot of work. 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 for your arms. This task was back-breaking. 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 days' worth in one go because, yes, you guessed it, my favorite topic, refrigeration.

23:30And without it, tortilla dough couldn't be kept overnight without fermenting. 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 komal. But this also took a lot of knowledge, how wet the dough should be and how thick, how long it should cook on the komal. 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.

24:01It's if you get a tortilla to puff, it means you're ready to marry. My partner Tim can in fact now get a tortilla to puff, which is good because we're already married. Roxana told us that the puff, that's a key part of the anatomy of a perfect tortilla. The thick part is called the loin, and what inflates when you put it on the comal is called the belly. The tortillas here function 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's what served as a napkin. 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.

24:47There'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. 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 at la ayuda 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 uh 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 you know i think i think like a couple dozen core shapes and then lots of different names to confuse people in between there may be a zillion different names for things made from masa, but there's also lots of different names for corn itself.

25:56Just 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 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 terminology or whether it's young corn versus older corn, or it's been shucked. Those are all like all different terms. 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. I mean, corn is life.

26:28It is like there's very little separation, if any, between literally the life that we have and corn itself. We are inextricably linked. You know, we come from corn and corn comes from us. David told us this belief goes deep. It's echoed in all sorts of different origin stories from the region. The maize god is very big in Maya art and religion. There are these origin stories of these twins who do all these feats and defeat bad gods, and then their father is the maize god, and they sort of rejuvenate him. David said that Corrin 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.