Nixtamalised masa: what it is, how it is made and its uses

What is it?

Nixtamalised masa is the foundation of Mexican maize cookery: a moist, pliable paste produced by grinding nixtamal (maize cooked with quicklime) to a smooth, workable texture. It is the fundamental ingredient for tortillas, tamales, tlacoyos, sopes, gorditas, huaraches, tetelas, totopos and virtually all Mexican antojitos. Its traditional preparation involves several stages: cooking the maize with lime, letting it rest, draining it, rinsing it and grinding it on a metate or in a mill. Nixtamalisation, a technique developed in Mesoamerica more than 3,500 years ago, transforms the maize by releasing niacin, improving the availability of amino acids and providing bioavailable calcium. Nixtamalised masa is thus not only delicious: it is one of the most nutritionally balanced staple foods of the pre-Hispanic world.

Origin and history

Nixtamalised masa has existed since the invention of nixtamalisation in Mesoamerica, a technique documented for at least 3,500 years at archaeological sites in the Soconusco (Chiapas) and Tehuacán (Puebla). The name nixtamal comes from the Nahuatl nextamalli (nextli: ashes, tamalli: cooked dough), reflecting the original use of alkaline ashes before quicklime was adopted as the standard method. In the sixteenth century, Fray Bernardino de Sahagún described in detail the complete process of making masa and its use in tortillas and tamales. Nixtamalised masa remained a universal domestic technique in Mexico until the twentieth century, when three innovations appeared: urban nixtamal mills (which cook the maize and grind it to sell masa by the kilo); industrial tortilla machines (which produce tortillas in series); and instant masa flour, Maseca, developed by GIMSA in the 1940s and 1950s, which makes masa with nothing more than added water. These innovations democratised access, but opened a debate about nutritional and sensory quality.

Characteristic ingredients

The traditional preparation of nixtamalised masa follows several stages: first, the dried maize (white, blue, yellow, red or cacahuazintle maize) is cooked with water and quicklime (1-2% of the weight of the maize) for 1-2 hours over a low heat. The heat is turned off and the maize is left to rest overnight (12-15 hours). During this rest, the grain absorbs water, the lime dissolves the coating of the pericarp and the chemical transformation known as nixtamalisation gets under way. The next day, the nejayote (the yellowish water) is drained off, the grain is rinsed several times with clean water in a pichancha and the result is nixtamal: whole kernels, soft, free of skins. This nixtamal is ground on a metate or in a mill to produce masa. The final texture should be smooth, slightly moist, pliable and lump-free. Masa types vary by use: masa for tortillas is more fluid; masa for tamales is mixed with lard and beaten until it floats in water; masa for tlacoyos and sopes is firmer. Nixtamalised masa keeps for 1-2 days refrigerated; it loses quality quickly through oxidation.

Cultural significance

Nixtamalised masa is Mexico's most representative food and stands at the centre of the country's gastronomic heritage. Traditional Mexican cuisine, declared Intangible Cultural Heritage of Humanity by UNESCO in 2010, explicitly recognises nixtamalisation and masa-making as a fundamental technique. The tortilla, masa's direct descendant, is the daily food of more than 100 million Mexicans, with an annual per capita consumption of roughly 75 kg. Nixtamalisation is documented by the FAO and by nutritionists as one of the world's most important culinary techniques: it prevents pellagra (niacin deficiency) and provides bioavailable calcium. In recent decades, the "Sin Maíz no hay País" (No Maize, No Country) movement and projects such as Maizajo, Itanoní (Oaxaca) and numerous artisan tortillerías have championed traditional nixtamalised masa against the spread of instant flour. SADER (Mexico's Ministry of Agriculture) and CONAGUA promote the recovery of native maize varieties and traditional nixtamalisation practices in producing villages.

Frequently asked questions

What is the difference between nixtamalised masa and instant maize flour?

Nixtamalised masa is made from lime-cooked maize ground fresh; it has a moist texture, a deep maize flavour and superior quality for hand-made tortillas. Instant maize flour (Maseca, Minsa) is dehydrated nixtamal in powder form; it is reconstituted with water and is convenient, but yields tortillas with flatter texture and flavour. Both share the nutritional benefits of nixtamalisation.

What does nixtamalised masa taste like?

It has a deep flavour of toasted maize, with earthy, aromatic notes released by the volatile compounds generated during lime cooking. Blue maize masa carries more fruity, sweetish notes; cacahuazintle masa is milder; yellow maize masa is more intense. Any fresh nixtamalised masa should smell intensely of maize and carry no bitter notes (a sign of residual lime).

How do you make nixtamalised masa at home?

Rinse 1 kg of dried maize and place it in a pot with 2 litres of water and 10 g of quicklime. Boil for 1-2 hours until the grain can be bitten through and its skin slips loose. Leave to rest overnight. The next day, drain it, rinse it 2-3 times with clean water, rubbing the grain to remove the skins, and grind it on a metate or in a mill. The result is fresh masa ready for shaping tortillas.

Where does nixtamalised masa come from?

Nixtamalised masa originated in Mesoamerica, with archaeological evidence going back at least 3,500 years. It was developed in what is now southern Mexico and Central America. Today it is produced throughout the country, with regional traditions especially well preserved in Oaxaca, Chiapas, Puebla, Tlaxcala, Michoacán, Guerrero and central Mexico.