Nejayote: what it is and what nixtamal water is used for

What is it?

Nejayote is the yellow, alkaline water that results from cooking maize with quicklime during the nixtamalisation process. Cloudy in appearance and with a very high pH (12-14), it contains dissolved lime, maize pericarp, starches and released nutritional compounds. Although it is traditionally considered a by-product of nixtamal, nejayote has culinary, medicinal and ritual uses among the indigenous peoples of Mesoamerica. It is used as a tenderiser in some stews, as a thickener in regional atoles and, in minimal quantities, as a remedy for reflux and acidity. It is also a central topic in debates on sustainability: industrial tortillerías generate large volumes that require special environmental treatment owing to their organic load and alkalinity.

Origin and history

Nejayote is as old as nixtamalisation itself, a technique developed in Mesoamerica at least 3,500 years ago. Archaeological evidence in Soconusco, Chiapas, shows pots with residues of maize cooked with lime dated to 1500 BC. Bernardino de Sahagún, in the sixteenth century, describes in his Historia general de las cosas de Nueva España the complete nixtamalisation process and mentions the handling of the cooking water. The Nahua peoples gave it the name nejayotl (from nextli, ash, and ayotl, water), reflecting its alkaline composition. For centuries it was an unavoidable part of the domestic maize cycle: the cooks separated it from the nixtamal, kept it for specific uses and discarded it in gardens as fertiliser. With the industrialisation of nixtamal in the twentieth century, the handling of nejayote became an environmental problem. Today researchers at the IPN and UNAM are working to make use of it as a functional ingredient, fertiliser or raw material for antioxidant extracts.

Characteristic ingredients

Nejayote is an alkaline calcium solution that contains valuable maize components: arabinoxylans, ferulic acid, soluble fibre and minerals. Its pH is around 12-14, which makes it caustic to the touch if concentrated. In traditional cooking it is used diluted: a tablespoon of nejayote can be added to dried beans to soften them more quickly, thanks to the softening of the skin by the alkalinity. In atoles of certain regions, such as chileatole or cooked-maize atole, the cooks add a touch to give viscosity and a characteristically mineral flavour. In Rarámuri and Nahua cooking, nejayote is mixed with ash to prepare the dough for special tamales. The difference between home and industrial nejayote lies in the concentration: the home-made one, made with little lime, can be used; the industrial one requires neutralisation before being discharged. Recent studies propose it as a food supplement for its fibre and antioxidant content.

Cultural significance

Nejayote is a material manifestation of the ancient system of the milpa and maize cooking, declared Intangible Cultural Heritage of Humanity by UNESCO in 2010. In indigenous communities, its handling is part of the culinary know-how passed down among women over generations: knowing how much lime to use, when to separate the nejayote and how to use it or discard it respectfully. Some Nahua traditions consider that throwing away nejayote without respect brings bad omens, so it is returned to the earth as an offering to the maize. From an environmental perspective, nejayote has become a symbol of the industrial impact of the tortilla: Mexico produces millions of litres a day that, without treatment, pollute rivers and soils. That is why initiatives such as those of the IPN, UAM and SADER seek to revalue it as a resource, not waste, connecting science and ancestral milpa tradition.

Frequently asked questions

What is the difference between nejayote and nixtamal water?

They are synonyms: nejayote is precisely the yellowish water left after cooking maize with quicklime in the nixtamalisation process. It is also called nixtamal water or the water of maize cooked with lime. Its characteristic colour and smell are due to the pericarp pigments and the dissolved lime.

What does nejayote taste like?

It has a bitter, alkaline and mineral flavour, with notes of quicklime and toasted maize. It is not consumed directly because of its high alkalinity, but diluted in stews it provides a subtle earthy touch. Its characteristic smell is described as slightly soapy, typical of calcium hydroxide solutions.

How is nejayote used in cooking?

A tablespoon of home-made nejayote (diluted) can be added to the cooking water of beans to speed up their softening. Some traditional cooks use it in regional atoles to give body and a mineral flavour. It is never used pure or in large quantities because of its alkaline pH, which is irritating.

Where does nejayote come from?

Nejayote originates in Mesoamerica, linked to nixtamalisation, which has been practised for 3,500 years in what is now Mexico, Guatemala and Belize. The name comes from the Nahuatl nexayotl or nextlayotl, derived from nextli (ash) and ayotl (water), referring to its origin as water mixed with lime.