How to make homemade nixtamal for corn tortillas

If you want to make truly authentic corn tortillas - the kind that smell of the milpa, that taste of real earth and maize - you need to start at the very beginning: nixtamal. Nixtamalisation is the pre-Hispanic process that transforms dried maize grains into soft, nutritious, flavour-packed dough. Without nixtamalisation, maize is just another cereal. With nixtamalisation, it becomes the foundation of one of the world's great cuisines.

In this article we teach you how to make homemade nixtamal step by step, with materials you can get in the UK, so you can prepare your own maize dough for tortillas, tamales, tlacoyos, sopes and any snack you fancy.

What is nixtamalisation?

Nixtamalisation is a chemical process discovered by the Mesoamerican civilisations more than 3,500 years ago. It consists of cooking dried maize in water with lime (calcium hydroxide, Ca(OH)₂) and leaving it to rest for hours. This process achieves several extraordinary things:

• It releases nutrients: Un-nixtamalised maize has niacin (vitamin B3) bound to proteins that the human body cannot absorb. The lime breaks these bonds and releases the niacin, preventing pellagra (a disease caused by niacin deficiency).
• It increases calcium: The lime treatment adds calcium directly to the maize grain.
• It improves the texture: The lime softens the outer husk of the grain (pericarp), which allows it to be peeled and ground easily to make a smooth dough.
• It develops the flavour: Nixtamalised maize has a complex, slightly alkaline flavour that is impossible to obtain any other way. It is the flavour we associate with authentic corn tortillas.
• It improves preservation: Nixtamalised dough keeps better than raw maize flour.

This discovery was so important that when Europeans took maize to Europe and Africa without the nixtamalisation process, the populations that depended on maize as a staple suffered epidemics of pellagra. The Mesoamericans had solved this problem 3,500 years earlier.

The ingredients you need

• Dried maize for nixtamal: 500g of dried maize kernels. In the UK, look for dried maize in Mexican or Latin shops. You can also use popcorn maize (not ideal but it works) or dried maize from wholefood shops. White or heirloom maize is best if you can find it.
• Lime (calcium hydroxide): 1-2 tablespoons. It is sold as 'cal', 'cal for nixtamal' or 'food-grade lime' in Mexican shops. It is also found as 'pickling lime'. Make sure it is pure calcium hydroxide, without additives.
• Water: Enough to cover the maize amply (about 2 litres for 500g of maize).

The process, step by step

Step 1: Clean the maize

Check the maize kernels and remove any stones, damaged grains or impurities. Rinse briefly in cold water.

Step 2: Prepare the lime water

In a large pot (preferably stainless steel or enamel; avoid aluminium), heat 2 litres of water over a medium-high heat. When it is hot but before it boils, add 1 tablespoon of lime. Stir until it dissolves. The water will turn slightly whitish.

Ratio: The general rule is 1 tablespoon (10-15g) of lime per 500g of maize. If you add too much lime, the maize will turn yellowish with a strong alkaline flavour. If you add too little, it will not peel well.

Step 3: Cook the maize

Add the cleaned maize to the lime water. Raise the heat and bring to the boil. Once boiling, lower to a medium heat and cook for 30-45 minutes. The maize is ready when you can peel the outer husk of the grain easily with your fingers (do this carefully, it is hot). The husk will come away like a thin, transparent skin.

Signs it is ready:

• The husk peels off easily when rubbed
• The grain is soft but not falling apart
• The water has turned dark yellow/golden
• It smells of cooked maize with a mineral touch

Step 4: Rest (the nejayote)

Remove from the heat and leave the maize in the lime water (called 'nejayote') overnight, at least 8 hours. This rest is crucial: during these hours, the lime keeps penetrating the grain, softening the structure and transforming the nutrients. Do not skip this step.

Step 5: Wash the nixtamal

The next day, drain off the lime water (nejayote). Rinse the maize thoroughly in cold water, rubbing the grains between your hands to remove the husk (pericarp) and the excess lime. Wash 3-4 times until the water runs clear and the grains are clean, with no husk remaining.

The clean, peeled grains are the nixtamal. They are soft, swollen and ready to grind.

Step 6: Grind the nixtamal

Here comes the step that requires the right equipment. In Mexico, nixtamal is ground on a stone mill (metate or hand mill). At home, you have these options:

• A powerful food processor: The most accessible option. Process the nixtamal in batches with very little water, stopping and scraping the sides frequently. The result will not be as fine as a stone mill, but it works.
• A hand meat grinder: If you have a hand grinder with a fine disc, pass the nixtamal through 2-3 times until you get a smooth dough.
• A manual maize mill: If you are taking this seriously, invest in a manual maize mill (Victoria, for example). They are found online and in Mexican shops. It is the best home option.
• A metate: If you have access to a metate (volcanic grinding stone), this is the ancestral method that produces the finest dough with the best flavour. It is a considerable physical workout.

The resulting dough should be soft, moist and malleable - like soft modelling clay. If it is too dry, add water a little at a time. If it is too wet, leave it to rest uncovered for a few minutes.

From dough to tortilla

With your nixtamal dough ready, you can make tortillas by following these steps:

1. Form little balls of dough the size of a large walnut (30-35g for taco tortillas).
2. If you have a tortilla press: place the ball between two sheets of plastic (a cut-up carrier bag) and press. If you do not have a press: flatten between two chopping boards lined with plastic, or use a heavy plate.
3. Heat a comal or iron pan over a medium-high heat without oil.
4. Place the raw tortilla on it. Cook for 45-60 seconds until the edges dry slightly.
5. Turn. Cook for a further 60 seconds. The tortilla should puff up partially (a sign that the dough is well made).
6. Turn one last time for 15-20 seconds.
7. Place in a tortilla warmer or wrapped in a clean tea towel.

A homemade nixtamal tortilla is a completely different experience from any shop-bought tortilla. The aroma, the texture, the flavour - everything is more intense, more real, more connected to thousands of years of culinary tradition.

Other uses for nixtamal and the dough

With the same dough you can make:

• Tamales: Beat the dough with lard and stock until fluffy.
• Sopes: Thick tortillas with pinched rims to hold salsa and stews.
• Gorditas: Thick dough filled with beans, chicharrón or cheese, cooked on a comal.
• Tlacoyos: Ovals of dough filled with bean, broad bean or curd cheese.
• Atole: Dough dissolved in water with cinnamon and sugar, cooked until thickened.

The dough keeps refrigerated for 2-3 days wrapped in plastic. It can also be frozen in portions for later use.

The quick alternative: nixtamalised maize flour

If this whole process seems like too much (and it is understandable, it is a two-day project), the alternative is to use nixtamalised maize flour such as Maseca or Minsa. Simply mix the flour with warm water following the packet instructions. The result is not as good as fresh nixtamal, but it is very decent and ready in 5 minutes.

But at least once in your life, make homemade nixtamal. It is an experience that connects you with 3,500 years of Mesoamerican culinary wisdom. And when you bite into that first tortilla made completely from scratch, you will understand why maize is sacred in Mexico. Visit our recipes for more authentic Mexican cooking techniques.