Nixtamalisation: what it is, how it's done and why it matters

What is it?

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

Origin and history

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

Characteristic ingredients

The traditional nixtamalisation process has several steps: 1) Dried maize is boiled in water with slaked lime or plant ash (about 1% of the weight of the maize) for 30-60 minutes. 2) The mixture is left to rest in the cooking water (called nejayote) overnight or for between 8-14 hours. 3) At dawn the maize is rinsed to remove some of the lime and the pericarp (husk). 4) The wet maize is ground on a metate or stone mill to obtain nixtamal dough. 5) The dough is shaped into tortillas or used for tamales and other treats. 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. The 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 landraces are nixtamalised with lime or ash, yielding doughs with unique flavours and colours (white, yellow, blue, red, black, speckled).

Cultural significance

Nixtamalisation is the most important technique of Mexican and Central American cooking and a pillar of UNESCO Intangible Cultural Heritage of Humanity (traditional Mexican cuisine, 2010). Native stone-nixtamalised maize is at the heart 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 tortillerías such as Maizajo, Tortillería Nixtamal (Maíz Criollo Kuxa) and Molino El Pujol in Mexico City have recovered native maize and traditional nixtamalisation as their banner. Chefs such as Enrique Olvera (Pujol), Jorge Vallejo (Quintonil), Carlos Salgado (Taco María in California) and Jesús 'Chuy' Cervantes (Atelier Crenn) have taken nixtamal to international haute cuisine. Native maize is threatened by NAFTA/USMCA and transgenics; movements such as Sin Maíz No Hay País 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 food it causes pellagra (a B3 deficiency). The 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 diet for more than 3,500 years.

What is the difference between nixtamal dough and Maseca flour?

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

How is nixtamalisation done at home?

Whole dried maize is boiled with water and slaked lime (1 teaspoon per kilo) for 30-45 minutes. It is left to rest overnight or for 8-14 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 dough 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 in Mesoamerica, developed at least 3,500 years ago, possibly by the Olmecs of the Gulf coast or the Mokaya of the Chiapas Pacific coast. It is a pan-Mesoamerican technique practised by the Aztecs, Maya, Zapotecs, Mixtecs, Totonacs, Otomí and all the peoples of central and southern Mexico and Central America. Its most detailed description is in Sahagún's Florentine Codex (1577).