Unlocking Nixtamal

There’s a list of foods that you can’t cross the border with, including meat, fish, alcohol, and fruit. Tortillas, however, are in the clear. So on every family visit across the busiest port of entry in the Western hemisphere—the one dividing San Diego and Tijuana in San Ysidro’s Port of Entry—was punctuated by an obligatory stop at the súper, usually Calimax, to pick up a few stacks of freshly made tortillas. At the dreaded three-hour border crossing, we’d follow the well-rehearsed motions: show our passports, be quiet unless spoken to, and await the routine question that border patrols ask with a tinge of intimidation: “Anything to declare?” My mom, with lightness in her voice to diffuse the tension, would respond with one word: “tortillas,” and the patrol would gesture for us to cross.

The tortillas de maíz we’d get in Tijuana were so different from the American ones we’d buy in San Diego—and were worth the trouble every single time. The difference? A 3,500-year-old technology developed by Mesoamericans that’s still in use today, transforming maíz from grain to sustenance. It’s the backbone of approximately 605 Mexican dishes, and what we know in Mexico as nixtamal. Tender, freshly made tortillas that honor the process are an elemental expression of nixtamal; American grocery store corn tortillas typically alter the alchemy to achieve longest possible time on the shelf; this modification affects both flavor and texture.

Nixtamalization, when done properly, spins corn into gold: taking something that’s of little nutritional value and alchemizing it into a source of nourishment that has carried generations. Corn that has been dried on the stalk—known as maíz—is boiled down with water that’s been mixed with ash, or calcium hydroxide (known as cal). The alkaline quality of the mixture softens the kernels enough to make it possible to peel off their inedible external shell, known as the pericarp, making the corn more digestible and its nutritional benefits more bioavailable (that is, easier for your body to absorb). In the process, they also excrete a gel-like substance, which helps make the mixture perfect for grinding into masa. The word nixtamal—pronounced by giving the letter x a soft “sh” sound—puts together two Nahuatl terms: nixtli meaning “ashes,” and tamalli meaning “cooked maíz masa.” It’s the dough that—when nixtamal first originated in 1,000 B.C.—was used to make tamales, wrapped and steamed maíz cakes, and maíz drinks, like the thick and warming atole and cool fermented tejuino. Tortillas came after.

I carried my Tijuanense piece of nixtamal across the border in burgundy-colored wrapped parchment paper—they were expertly folded to insulate the warmth. Condensation tends to cloud inside the package from the heat, causing the tortillas to become too tender and stick to one another—making it difficult later on to separate them. So once home, my brother and I would sit at the table together, busy with the task of peeling the tortillas off of one another, and restacking them before storing in the fridge.

En el otro lado, what we call the American side of the border in Tijuana, the most immediately available tortillas were short stacks of stiff rounds stuffed in plastic bags at grocery stores. Extra cal or preservatives, such as parabens, help these tortillas last on the shelves, but tend to make them drier, too, and easier to crack. Those tortillas didn’t need to be restacked; they’d just fly into the fridge. These shiny plastic-bagged tortillas also emanate a foreign smell: a scent that can resemble ammonia or copper, which translates to the sour flavor that cookbook author Lesley Téllez mentions in the nixtamal guidebook, Nixtamal: A Guide to Masa Preparation in the United States. These mass-produced tortillas give dishes that rely on them as the star ingredient, like tacos or quesadillas, a noticeably different profile.

It’s no secret that fresh tortillas de maíz reign supreme. Their wafting aroma—a flutter of nut, oat, and a touch of smoke—romances the senses, inviting a host of fillings and flavors to contrast and complement. Their tender texture, which can be crushed and then sprung back into shape, boasts a light chew with just enough resistance. But it goes deeper too: a fresh tortilla connects the hearth, the Mexican table, and the soul—it’s a spiritual experience, like Enrique Iglesias sings in his 1995 hit. And what makes fresh tortillas so extraordinary, what makes the difference, is that they are a product of nixtamal, that within their circular flat round edges they contain eternal mysteries, entire civilizations, and one of the biggest technological breakthroughs still practiced in today’s modern age.

“The first time I tried a corn tortilla made from real corn was when I lived in Mexico City,” Téllez writes. “I nearly cried because it tasted so good, and because I’ve been deprived of the real thing for so long.”

Call it third wave masa, if you will: an era of fragrant tortillas, tender tamales, and meticulously sourced heirloom corn. It’s been 100 years in the making.

The real thing starts with maíz—a cereal plant that’s harvested once it’s dry, unlike sweet corn, which is harvested when its kernels are juicy and hydrated. Sweet corn is what we use for antojitos like esquites. But when we talk about tortillas, masa, and nixtamalization—the process that unlocks it all—we must begin with maíz.

From maíz to nixtamal

Before it became maíz, there was a grass called teocintle. Its earliest iterations in Mesoamerica can be traced back over 8,000 years. Maíz turned out to be a resilient crop, “capable of adapting to the most diverse ecological conditions,” Carmen Wacher, Ph.D., from Universidad Nacional Autonoma de Mexico (UNAM) writes in her study, “Nixtamalization, a Mesoamerican technology to process maíze at small-scale with great potential for improving the nutritional quality of maíze based foods.” It grows not only in Mexico but across the Atlantic Ocean in eastern, southern and western Africa, the Caribbean islands, and in Europe. China grew 260.78 million tons of maíz in 2019. But maíz is incapable of self-seeding, unlike cilantro and spinach, which can propagate on their own—maíz is dependent on mankind to be stewarded into the world.

It’s a crop that took a couple thousand years of domestication and grew to become the key sustenance for emerging Mesoamerican civilizations like the Mayans. This is why the renowned anthropologist Guillermo Bonfil-Batalla wrote, “maíz is a cultural creation.” It didn’t spring up by accident—the cultivation of maíz was intentional.

Along with beans and squash, maíz was one of the first agricultural crops to be harnessed by people in Mesoamerica. In Mexico this crucial trio of foods—squash, beans, and corn—is known as milpa, and for some Native Americans it is called the three sisters. However, unlike beans and squash, maíz wasn’t a food one could simply harvest and consume. It required transformation. It required the human touch.

“Maíz in and of itself wasn’t that nutritious,” Sofia Casarin explains. She is a maíz purveyor from Tamoa in Mexico City and spoke with me over Zoom about the role that nixtamal plays in Mexican cuisine and culture. “Making nixtamal is one of the most important discoveries of our civilization, [especially] to be able to subsist off of maíz as a principal carbohydrate.”

Part of what makes nixtamalization so culturally important in places like Mexico is that nixtamal awakens a rich host of nutrients that are otherwise asleep in maíz. Amanda Gálvez, Ph.D., a professor in UNAM for the department of food and biotechnology in Mexico City, writes in Masienda’s nixtamal guide that nixtamalizing corn makes its essential nutrients easier for our bodies to absorb. Nixtamalized maíz products contain 13 times more calcium than the maíz itself before nixtamalization, she writes, and can even function as a diet’s main source of calcium. Calcium, one of the most critical minerals in the body, supports strong bones, teeth, muscles, and a healthy nervous system, among other important functions. Aside from calcium, nixtamal unlocks vitamin B3, an essential nutrient otherwise known as niacin, which helps our bodies turn food into energy. “We need that [niacin] to survive,” chef Dave Smoke-McCluskey of Corn Mafia in South Carolina says over a phone call. And, as if by magic, when nixtamal is paired with beans, the combination creates a complete protein—meaning that together they contain all nine essential amino acids necessary in a human diet. It’s an entirely life-giving product that arises from the shadows of death—using wood and sea shell ash, or calcium, made from limestone that’s born of fossilized plant and animal remains.

Chef Mercedes Golip, an arepa enthusiast and educator in New York, tells me that in Venezuela, the process is called maíz pelado or pela’o, not nixtamal. Pelado translates to “peeled.” It refers to the pericarp (the hard inedible outer shell) that gets peeled from the kernel as you wash away the nixtamal liquid and rinse the nixtamalized maíz, which is known as hominy if you keep rinsing and don’t make masa. Golip adds that arepas peladas are typically made from corn that’s processed with the ashes taken right from under the Venezuelan budare that is used to cook arepas once they’re formed. The cycle continues.

Chef Golip’s affection toward nixtamal doesn’t stop at traditional arepas. She uses different natural colors, presses flowers, and even experiments with adding miso to make what she calls masa-miso. “The flavor is mildly acidic with floral and umami notes,” she says of the fermented masa, adding that she uses the masa-miso to thicken and inject more flavor to soups and stews.

Over 2,500 miles north from Venezuela, in northern New York, Indigenous people were also peeling pericarps with ash. Chef Smoke-McCluskey tells me they call the process lyeing or washing. Today, he’s one of only a few people making hominy grits in South Carolina; he explains that he does so in his Northeastern Mohawk tradition. “We generally use hardwood ash to make a weak lye solution. It’s where the term lyeing comes from, but it’s all part of the same process,” Smoke-McCluskey says. The process creates a slurry, the liquid taking on the muddied color of ash. This hominy makes for hearty soups, and the masa is stirred together with beans to form a thick puck shape that gets cooked at a boil—until it dances, as chef Tawnya Brant describes in this recipe video for Haudenosaunee cornbread. The cooking liquid retains some nutritional value and shouldn’t be discarded, chef Brant explains, urging viewers to save it for tea or to use as nourishing cooking liquid.

Though its alimental and cultural value has been proven over and over again, the exact origins of nixtamal remain a mystery even to those who have dedicated their lives to studying it: “We’ve talked to anthropologists, agronomists, scientists—there is no definitive answer” to explain the inception of nixtamal, Casarin says over Zoom. But the tools that birthed nixtamal have been found. It’s blueprint: remnants of maíz seeds and ash in a clay pot.

“The first registry of nixtamal that was found was inside of a clay pot,” she explains, telling me that clay pots, which existed long before nixtamal, were usually shaped like pregnant bellies—perhaps as symbolism of the wonders that clay pottery would birth.

Some of the tortillerias, grocery stores, and restaurants that sell fresh masa across the country.

The nixtamalization process

“It’s interesting to think about how the first corn kernels were nixtamalized. Who did it? Was it an accident? Did the corn speak to them?” These are the questions that chef Denise Vallejo of Alchemy Organica, who prides herself in sourcing organic ingredients for her pop-up, shares with me over text. “You can’t really pound dry corn into anything, so somewhere down the line someone figured out how to add ash or lime in the cooking process, which made the corn bloom.”

The very process of nixtamal is what made maíz such a nourishing and highly revered crop, and why eating it daily provided a multitude of benefits. But when Italian and Spanish colonizers decided to take maíz from the New World and make it a diet staple in Europe, in what is referred to as the Columbian Exchange, they missed one key element: nixtamal. This proved to be a fatal oversight. People who rely on unhulled maíz alone risk a niacin deficiency disease called pellagra, which includes symptoms of skin lesions, loss of hair, insomnia, dementia, and sensitivity to light. If this sounds like the spooky stuff of lore, that’s because there might be a connection. Some scholars believe this disease was the origin of the vampire myth. Corn without nixtamal took its toll and left behind bloodthirsty legends of the undead.

Though nixtamalization is an ancient practice, and technologically, there have been some advancements, the bones of it have stayed very much the same. Emmanuel Galvan, who started Bolita, a micro molino and tortilleria in Oakland, California, during the pandemic, walked me through the process of nixtamalization, step-by-step:

• Step 1: Galvan starts by bringing the water to a boil in a stainless-steel or enamel pot and adds one percent of cal, or calcium hydroxide, per total weight of maíz. He says boiling the cal with the water helps ensure that it’s well incorporated. He adjusts the cal in his recipes depending on the color of the maíz, saying that too much cal for red maíz turns it gray, and too much for blue maíz turns it green, giving off a copper penny flavor.

• Step 2: Once it comes to a boil, he adds the maíz and brings the heat down to a simmer, cooking the maíz gently for about 20 minutes.

• Step 3: After the mixture is done soaking, he gives it a rinse to clean it and rub off the pericarps or kernel hulls. This is nixtamalized corn or nixtamal. At this step, you could continue washing your nixtamal maíz and have hominy. Hominy is what’s used in pozole and in soups all over the Americas—from the Iroquois in New York to Colombia. Hominy is tender and engorged in size, resembling a garbanzo bean. But washing off the nejayote—the liquid the maíz is cooked in—to produce hominy means washing off the gel released during nixtamalization that makes for ideal masa. It’s that gel that helps hold masa together.

From nixtamal to masa

Masa has a consistency close to that of Play-Doh. It’s smooth but slightly sandy, and when you scoop some out with your hands, you’ll notice some ridges are left behind in the crevice of the dough. Rolling it into a ball for tortillas is easy—the dough holds its shape even though it’s soft to the touch. Masa’s scent is mild and delicate, salty with a nutty hint reminiscent of oats, a touch of tang that can only be attributed to the calcium hydroxide used to prepare it.

Grinding nixtamalized maíz into masa is the final piece of a lengthy but extremely rewarding process. In Mesoamerican times, this ritual was completed using a metate: a rectangular, flat stone, usually porous and made from volcanic rock, with short legs, and a separate hand piece called a mano, or metlapil in Nahuatl. These tools have been used to grind washed maíz into fresh masa for thousands of years. In fact, the metate was already in the Americas, used for grinding seeds or juicing fruit before it was ever used to make masa. The earliest trace of metates found in the American Southwest date back to 5,500 to 8,500 years ago. Metates are traditionally used on the ground while kneeling, keeping the whole body engaged in the process. This positioning was seen as a way to show respect and admiration to the food being prepared: a gift from the gods. Using the mano to scrape the maíz in upward and downward motions, the nixtamal is transformed into the dough we know as masa.

Today, there are more convenient and time-efficient options for grinding masa, though the metate is still alive and well. Galvan says the simplest way to do it at home is with a food processor, but warns that it’s hard to get an even grind. For large batches of his masa, he uses a local restaurant’s large volcanic-stone molino. But for the most part, he says he uses a countertop model by Masienda called Molinito.

For those who feel called to make nixtamal at home, Chef Golip shares some good tips for storage if you can’t cook it all right away: “Since making masa from nixtamal is quite industrious, I like to make a big batch—two to four pounds—at once.” It can be frozen with good results, Golip says; just portion it out and create roughly flat discs and freeze them individually for 4–8 weeks. Thaw the disks in the fridge overnight before using.

Preserving the history and lineage of maíz, nixtamalization, and masa is the work of purveyors, farmers, chefs, and home cooks; keeping the recipes alive is a way to bolster a tradition that is at the heart of our identity, in Mexico and in the Americas at large. For Chef Golip, who considers corn to be at the cornerstone of her Venezuelan food culture, working with nixtamal and masa leads to crucial conversations about exile and finding comfort in a new home. In fact, she didn’t learn to make arepas peladas until she moved to the U.S. 15 years ago, and says that learning how to cook them in her New York kitchen has been an enriching journey. The arepa, she says, is essential to her food memories, and “it was and still is the daily bread of many native communities. We need to make an effort to preserve and honor it.” For now, Golip bridges the space between two countries in her New York kitchen, one arepa at a time.

Through Tamoa, Sofia Casarin and her partner Francisco Musi have focused on sourcing locally grown heirloom varieties of maíz—of which there are over 60 currently in Mexico. “We started working with maíz out of wanting to eat a better tortilla, because there are so many bad tortillas consumed now in Mexico,” Casarin explains. Beginning in the 1980s, the tortilla became an industrialized product, and many mass-produced tortillas were based on low-quality maíz that weren’t nixtamalized properly. Today, Tamoa’s maíz is used to make masa in Mexico and beyond, stretching across the Atlantic in Europe and north of the border in the U.S., where purveyors have increasingly focused on sourcing quality ingredients for a tastier tamal or tortilla.

Whether made with corn flour, known as masa harina, or made from scratch using nixtamal, masa carries an important legacy through many of the cuisines of the Americas. In Belize, where Mayan people reside, they cook a dish called salbute—red cabbage and shredded chicken on a fried puffed tortilla. In Guatemala, you’ll find tamales wrapped in banana leaf, and masa patties called garnachas, topped with ground meat and potato. Hondureños make pastelitos—stuffed masa half-moons that get fried to a golden crisp—and prepare fried cheese-and-masa capirotadas, served in a warming, brothy vegetable soup. Venezuelans pat their masa pelada into arepa-shaped pucks and slit them open horizontally, making a pocket perfect for cheeses, beans, avocado, meats, and more. In Mexico, we have a nixtamal dish for nearly every occasion, every season, and every course. In each country and region, our own iterations of maíz and nixtamal spin a golden thread that weaves through the Americas like a spiderweb; a rich history of humanity, with maíz and masa pulsing through it—alive across continents, and across international borders, alive in a stack of fresh-made tortillas.

Chef, cookbook author, and culinary anthropologist Fany Gerson is here to show you how the best tortillas are born: from scratch.

Originally Appeared on Epicurious