What Is Nixtamalization? The History Behind the Traditional Technique.

You’ve likely heard or seen the term at some point, but you might not know exactly what nixtamalization is or the details behind the process. Nixtamalization is a prehispanic traditional practice of preparing maize (harvested dried corn) that originated in Mesoamerica (present day Central and Southern México and Central America) thousands of years ago.

Nixtamalization was introduced around 1200 BC-1500. The technique transforms dry and practically inedible corn kernels into an important foundational ingredient, as explained by food anthropologist Rocio Carvajal on the podcast Pass the Chipotle.

Nixtamalization is used to make soft fragrant masa (corn dough that’s used to prepare culturally significant foods like tortillas and tamales). Masa is responsible for nourishing entire civilizations, including the Aztec and Mayan, and continues to be the bedrock of many Latin American diets, according to the International Maize and Wheat Improvement Center (CIMMYT).

Simply put, nixtamalization is the cooking and steeping of maize in water mixed with an alkaline solution. This solution, traditionally wood ash or food-grade powdered limestone (calcium hydroxide or Cal in Spanish), is diluted in water to release the maize’s nutrients and soften the kernels. Nixtamalization originated in Mesoamerica and is still commonly used today in present day Central and Southern México and Central America.

The term nixtamal (pronounced neex tah mal) comes from the Náhuatl word nextli meaning “ashes” and tamalli, meaning “cooked corn dough”. Nixtamal refers to the cooked maize that undergoes this alkaline process. The nixtamalization process makes corn more digestible and increases its nutritional value.

According to the CIMMYT, apart from altering the smell, the flavor and color of all maize products, nixtamalization provides several nutritional benefits including vitamin B3 niacin, calcium, and iron.

Without the nixtamalization process, it would be impossible to make tortillas or any other food made with masa. The dry maize kernels, with their outer hull intact, would just be corn flour or cornmeal.

Foods made with nixtamalized corn will produce a masa that is more flexible, and the foods made from it will have a better consistency, will cook more easily, and will have that irresistible texture and nutty aroma that we all know and love.

Much like the story of sourdough bread, no one knows exactly how or when people stumbled upon this technique of cooking maize, according to food writer and author Janet Long. And yet, just like with most great discoveries, it was probably through a series of accidents and experimentation.

After the domestication of corn, it is believed that Mesoamerican people, after much trial and error, tried boiling the kernels in a pot filled with water, and ashes from the burning wood came in contact with the cooking kernels. This caused a chemical reaction (the kernels would change color) that sparked not only their curiosity, but served as a turning point to better understand and prepare maize.

In a similar fashion, the use of calcium hydroxide (the powder resulting from scraping limestone) most likely resulted from grinding the maize on the limestone found on riverbeds. They observed how this element of nature interacted with the maize and paid close attention on how this affected their bodies.

In contrast to plain maize, nixtamalized corn was easier to work with, and produced a better tasting and enjoyable variety of foods as well as providing physical stamina.

Thanks to nixtamalization, corn was disseminated all over Mesoamerica and became their most important crop. It was a resource that sustained people for thousands of years, and continues to do so to the delight of many.

There is no exact recipe for nixtamalization, because all maize is not equal. In Mexico, for example, there are 59 species of heirloom corn, according to Rafael Mier, director of the Tortilla Foundation, who discussed the process on the Pass the Chipotle podcast. All varieties are different not only in color but in nutrients, levels of hardness, and starch. The hardest kernels will require more calcium hydroxide than the softer, starchier ones. Cooking times vary, and some varieties require longer steeping times, ranging from approximately 12 to 14 hours.

To preserve these heirloom varieties, it’s important to work with the growers since they are the experts at preparing a nixtamal that produces the best quality masa; they are the custodians of traditional food practices, therefore they need to be supported as they continue their work and pass along their legacy.

In the beginning, there is what we call an elote (fresh tender corn). When the elote is picked it is sold as corn on the cob, a popular vegetable during the summer months. When you leave the corn to mature on the plant, way past its ripening process, it will get increasingly hard and transform into a cereal as it absorbs all the nutrients until it completely dries out. Now called a mazorca (dried corn on the cob), it is picked and stored for several months until it’s time to prepare the nixtamal. The CIMMYT showcases a helpful infographic of the nixtamalization process.

When done by hand, you can remove the dried corn kernels from the olote (cob) using a variety of techniques.

One is rubbing the mazorca vigorously against an olotero (a wheel made of dried corn cobs wrapped tightly together). Another is rubbing a mazorca against a dry olote, and sometimes by using a knife or other homemade tools.

The kernels are collected in a basket and cleaned (picked through to make sure they’re free of debris).

Add water to a non-reactive pot which must be exclusively used for nixtamalization, as the process leaves traces of limewater (nejayote, meaning ‘ash liquid’) on the pot. Turn on the heat and bring it to a simmer.

Dilute the proper amount of wood ashes or calcium hydroxide in a small container of water, then add it to the cooking pot.

When the water is simmering, add the maize kernels. Cook the maize in alkaline water (the temperature should be between 160 to 190 degrees Fahrenheit), the time will vary according to the variety and hardness of the maize. When the outer hull is easily removed from the kernels, remove the cooking pot from the heat.

After cooking the kernels, let the maize soak in the alkaline water. The length of the soaking will depend on the hardness and color of the grain.

After soaking, drain the nejayote and rinse the kernels one to two times to remove the excess alkaline solution.

Now your nixtamal is done, ready to be ground into Masa and prepared into corn tortillas, sopes, pupusas, Arepas Peladas, tamales and all other popular forms of corn-based foods. This can be done either in a Tortilla Mill (Molino in Spanish) or in a Metate, a traditional grinding stone with a concave upper surface made of volcanic rock. You can use it whole as well, like the variety Cacahuazintle that’s used in pozole.

If not used right away, you can dry the nixtamal and store for a few months (the nixtamalization process acts as a preservative) or it can be ground into masa harina and used as instant nixtamalized corn flour.