Nixtamalisation: ancient technique of Mexican maize

What is it?

Nixtamalisation is the pre-Hispanic Mesoamerican technique of cooking dry maize with water and quicklime (calcium hydroxide) to produce nixtamal, the base masa of tortillas, tamales, atoles, tlacoyos, gorditas and practically the whole maize cuisine in Mexico and Central America. The word comes from the Nahuatl 'nextli' (ash or lime) and 'tamalli' (masa). The process releases essential nutrients in the maize kernel, especially niacin, calcium and amino acids, and radically modifies its texture and flavour. Without nixtamalisation, maize would be an incomplete food and Mesoamerican cuisine would have been impossible. The technique has been used in Mesoamerica for more than 3,500 years and remains the basis of everyday Mexican cooking, from neighbourhood tortillerias to Michelin-starred restaurants that have reclaimed native stone-ground nixtamalised maize.

Origin and history

Nixtamalisation emerged in Mesoamerica at least 3,500 years ago, possibly among the Olmec peoples of the Gulf coast or the Mokayas of the Pacific coast of Chiapas-Guatemala. The oldest archaeological evidence is burnt stones with lime and maize residues at sites such as Chiapa de Corzo. The Florentine Codex of Fray Bernardino de Sahagun (1577) describes 16th-century Mexica nixtamalisation in detail: maize was cooked with slaked lime in clay pots, left to rest overnight, rinsed at dawn and ground on metate. According to INAH, this technique was the most important nutritional innovation of Mesoamerica, alongside the complementary basket of beans, squash and chilli. The peoples of the North American altiplano (Pueblo, Hopi) and South America (Incas) also consumed maize, but without nixtamalisation, which limited its nutritional value. Pellagra (niacin deficiency) manifested in Europe when they took maize without the nixtamalisation technique, indirectly demonstrating Mesoamerican genius. The boom of industrialised maize flours (Maseca, Minsa) since the 1950s partially replaced traditional nixtamalisation, but the movement to reclaim native stone-ground nixtamalised maize has revitalised the technique from the 2000s.

Characteristic ingredients

The traditional nixtamalisation process has several steps: 1) Boil dry maize in water with slaked lime or vegetable ash (approximately 1% of the maize's weight) for 30 to 60 minutes. 2) Leave the mixture to rest in the cooking water (called nejayote) overnight or between 8 to 14 hours. 3) At dawn, rinse the maize to remove some of the lime and the pericarp (husk). 4) Grind the wet maize on metate or stone mill to obtain nixtamal masa. 5) The masa is shaped into tortillas or used for tamales and other snacks. The chemical effects are crucial: the lime releases the niacin (vitamin B3) bound in the kernel, transforms the pericarp making it easier to digest, increases available calcium, improves the availability of essential amino acids (lysine, tryptophan), and develops the characteristic aroma and flavour of nixtamal. Nejayote (cooking water) was considered a pollutant by industry, but today it is studied as a valuable by-product for its antioxidants and phenols. Native (criollo) maize varieties such as cacahuazintle, bolita, pepitilla, tabloncillo, conejo, jarocho and more than 60 Mexican races are nixtamalised with lime or ash, producing masas with unique flavours and colours (white, yellow, blue, red, black, mottled).

Cultural significance

Nixtamalisation is the most important technique in Mexican and Central American cuisine and a pillar of UNESCO Intangible Cultural Heritage of Humanity (traditional Mexican cuisine, 2010). Native stone-ground nixtamalised maize is the axis of the Mexican food sovereignty movement, in the face of pressure from transgenic maize and industrialised flours. Researchers such as Cristina Barros, Marcos Bucio, Rafael Mier and the Mexican Maize Tortilla Foundation document, promote and defend traditional nixtamalisation. Pioneering tortillerias such as Maizajo, Tortilleria Nixtamal (Maiz Criollo Kuxa) and Molino El Pujol in Mexico City have reclaimed native maizes and traditional nixtamalisation as a banner. Chefs such as Enrique Olvera (Pujol), Jorge Vallejo (Quintonil), Carlos Salgado (Taco Maria in California) and Jesus 'Chuy' Cervantes (Atelier Crenn) have taken nixtamal to international fine dining. Native maize is threatened by NAFTA/USMCA and transgenics; movements such as Sin Maiz No Hay Pais defend its sovereignty. Nixtamalisation is also being recognised as a natural fermentation technique by contemporary microbiology.

Frequently asked questions

Why is nixtamalisation important?

Without nixtamalisation, maize has bound niacin that the body does not absorb; consumed as a staple it causes pellagra (B3 deficiency). Lime releases the niacin and improves the digestibility of the kernel, provides calcium, and transforms amino acids to make them more available. It is the nutritional innovation that allowed Mesoamerican civilisation to flourish on a maize-based food supply for more than 3,500 years.

What is the difference between nixtamal masa and Maseca flour?

Nixtamal masa is obtained by grinding fresh, wet nixtamalised maize on metate or stone mill; it has a maize aroma, available calcium and deep flavour. Maseca or Minsa flour is industrially nixtamalised maize, dried and ground into fine flour; it is rehydrated with water for use. It is more stable and easier but has a flatter flavour and nutrients partially lost in the industrial drying.

How is nixtamalisation done at home?

Whole dry maize is boiled with water and slaked lime (1 teaspoon per kilo) for 30 to 45 minutes. It is left to rest overnight or 8 to 14 hours. The next day the maize is rinsed (not all the lime, just the excess). It is ground in a hand mill or blender with a little water until an elastic masa is obtained. It is shaped by hand or with a press to make tortillas, tamales or gorditas. It is a simple process but requires practice.

Where does nixtamalisation come from?

It originates from Mesoamerica, developed at least 3,500 years ago, possibly by the Olmecs of the Gulf coast or the Mokayas of the Pacific coast of Chiapas. It is a pan-Mesoamerican technique practised by Aztecs, Maya, Zapotecs, Mixtecs, Totonacs, Otomis and all the peoples of central and southern Mexico and Central America. Its most detailed description is in Sahagun's Florentine Codex (1577).