Making GMO-Free Corn Tortillas from Scratch: A Detailed Lesson in Nixtamal for Beginners

“Nixtamal” comes from the Nahuatl word nixtamalli which means “unformed corn dough.” Nixtamalization is the process  of soaking the corn in an alkaline solution, such as “cal” or wood ash.  This soaking process makes the corn more digestible and the nutrients in the corn more accessible to the body.  On a practical level, it makes the corn easier to grind and makes it easily form into a dough (masa) for use in tortillas, tamales, pupusas, tlacoyos and more.  To make posol (hominy), you skip the grinding process and simply boil the nixtamal corn in broth. 

Nixtamal has sustained our ancestors for thousands of years.  No one knows for sure when our ancestors first discovered the process of nixtamalization—the earliest evidence of nixtamal has been located in Guatemalan cooking equipment that is 3500 years old!  I think it quite powerful—at a spiritual and cultural level—to reclaim this practice by doing it yourself. 

Health benefits of nixtamal: 

  • Converts corn’s bound niacin to free niacin, making it available for absorption into the body.
  • Alkalinity improves the balance among essential amino acids, making more protein available.
  • Is rich in calcium, iron, copper, and zinc. After nixtamalization with cal, the corn has 750% more calcium! 
  • Eliminates certain carcinogenic fungus found in corn. 

Note: Industrially-produced tortillas no longer use the ancient process of nixtamalization and instead use an enzymatic process that produces a much inferior masa. There are still tortillerias in the US and Mexico that produce nixtamal but I fear their days are numbered. Blame NAFTA. 

Because it is hard to find organic, GMO-free masa in the Bay Area, I decided I would learn how to make nixtamal corn masa myself.  There are a lot of steps involved but it is not *that* difficult and totally do-able with a little practice and planning. 
And, nothing beats the taste of a tortilla made this way! It’s not spongy and sour like the fresher store-bought ones, nor dry and stiff like the older ones. The outside has a slightly toasted texture, the inside is tender but fully cooked. You can taste and smell the sweetness of the  corn. Plus, you are eating something that is entirely good for you, you are resisting GMO tortillas,  and you are connecting to an ancestral practice that is over 3500 years old.  

Making Nixtamal (allow 18-24 hours)

  • 2 cups dried dent corn
  • 2 tablespoons cal (slaked lime)
  • 6 cups water
  •      Rinse 2 cups dried dent corn.
  •      Use a large non-reactive pot (stainless steel, glass, or clay are all good). Read about non-reactive cookware here:
  •      Add 6 cups cool water to the non-reactive pot.
  •      Mix in 2 tablespoons “cal” to the water to create a “slurry”
  •      Add rinsed corn to the slurry. It will look like this: 
      Cook corn on medium heat for 45 minutes. Ideally, you want the water to just *barely* begin to come to a boil at exactly 45 minutes. This is not as hard as it sounds. The first couple of times you do it, you need to watch carefully. If it starts to look like it is about to boil before 45 minutes, turn the heat down a bit. If at 30 minutes, it is not even close, turn the heat up a bit. 

After 45 minutes, turn off the stove and cover the pot. Allow the corn to soak in the pot overnight and preferably for about 24 hours.
      After 18-24 hours, your corn will look like this:
Rinse the corn thoroughly under cool water.

Fill a deep bowl or pot with cool water. Add the corn and using your hands, rub the corn vigorously between your palms. You are trying to remove the outer layer of skin (the hull)—it should fall off pretty easily. Do NOT attempt to clean each kernel one at a time. That would be insane. Just use your hands to massage the corn. It might seem like nothing is happening because the skin is pretty thin but you should begin to see little bits of skin floating in the water. 

Pour off the top of the water along with the little pieces of skin that have been removed. I repeat this step about 10 times, until the water I pour off is almost completely clean. Strain the corn one last time.

After rinsing several times, your corn should now look like this:

Now, you are ready to grind the corn. Put a pan under the grinder to catch the masa. Put the strained corn in your grinder. I run my corn through the grinder a second time to get a softer dough. 

This is what the freshly ground nixtamal corn will look like: 

Take your freshly ground nixtamal and add ½ to 1 teaspoon of salt (I add 1 teaspoon but other recipes say 1/2 teaspoon). Start working the dough with your hands and add about 1 tablespoon of water at a time. Work the dough and add water until you have a nice ball of dough that sticks together, is smooth, but is not pasty. Take care not to add too much water or you will have a mess. I think I add between 1/4 cup and 1/2 cup of water.  I’ve heard if you add too much water, you can add some masa harina to get the masa back to the right consistency. But really, just add water in small increments and you will be fine. Your ball of dough should look like this:

Form balls about the size of a golf ball (or a wee bit smaller). I have found that this recipe (2 cups of dried corn) produces about 1 dozen medium sized corn tortillas.

Prepare your tortilla press and heat your comal (griddle). You want the comal hot when you put the first tortilla on. After the comal is hot you can turn the heat down from high to medium high. 

Line the tortilla press with two pieces of plastic. Thin plastic from a produce bag works best. Use scissors to deconstruct the bag into two equal pieces. Press the ball of dough between the two pieces of plastic. Push the lever down. Flip over and press again.


      Carefully peel the plastic off the top. Flip the tortilla so you are holding the tortilla on your left hand (if you are right handed) and the remaining plastic is facing up. Remove the plastic.

You now have a raw tortilla on your hand. (Kind of embarrassing that I used a Whole Foods plastic bag. I swear, I hardly ever go there. But their bags really work for this purpose. Ha!) 

Ever so carefully, place the tortilla on a hot comal. This is the part that I have found takes practice. Don’t despair. It gets easier with practice and over time you won’t even remember why you thought this was difficult. I think it might be easier with freshly ground corn than with the masa you buy at the tortilleria. You’ll develop your own technique for getting that tortilla perfectly placed on the comal. (I know some people are laughing at me right now. That’s OK. Decolonization is a practice in humility. I messed up a bunch of tortillas before I got the hang of it.)

After the edges of the tortilla start to turn up slightly, flip the tortilla. Continue cooking for a few minutes. You can flip the tortillas a few times until they look done.

Put the finished tortillas between a folded clean dish towel.  Don’t worry too much if you think the tortilla is still slightly raw in the inside. Make more tortillas and let them rest together in the clean towel. They will continue cooking on the inside. By the time you serve them they will be perfect. ENJOY!

Before bring trying this at home, I suggest you also read this informative blog post:

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