Corn Flour and Masa 101

There is very little consensus on what people first picture when they hear the words “corn flour.”  I think of the flour used for masa, a dough to make tortillas, gorditas, and many other Mexican corn products.  I understand in Great Britain it will bring images of a white and very fine product, what is known as Maizena™ in Mexico, some South American and European countries, or corn starch in Canada and the US.  And how about cornmeal?  A “meal” defines how coarse a grain is ground, but in this case, it is a different product from the other two mentioned before.  The differences amongst all these corn flours can be classified according to four aspects during processing: pre-cooking before grinding; additional ingredients; grinding coarseness (fine, medium, etc.); and whether the grain is used whole, or refined, in which the germ and outer layer (hull and bran) are partially or totally removed:

00 anatomy of a corn kernel My Slice of Mexico

I found seven different corn flours at my local supermarket and international stores, pictured at the top of the post; some were made from white corn, others from yellow corn, and were different in terms of the four processing aspects, as summarized in the chart below:

Corn flour comparison chart My Slice of Mexico

And their appearance reflected their characteristics:

corn flour samples My Slice of Mexico

I am now going to concentrate on the types that are used for masa; therefore, Maizena™ and the two cornmeal flours will not be considered for this particular post.  The ones created especially for this application are Maseca™ and Bob’s Red Mill™ masa harina; whole dry corn kernels are soaked and cooked in water with lime, which is not the citrus fruit, but the common name for calcium hydroxide (cal, in Spanish.)  This process has been known to Mexican cooks since pre-Columbian times, called Nixtamal, from Nahuatl nextli – ashes and tamalli – wrapped; Nixtamalization is the English word.  The use of an alkaline compound (such as lime, or ashes) partially dissolves hemicellulose, present in the corn cell walls and responsible for bonding them together; dissolving hemicellulose loosens the hulls.  The cooking process also softens the grain, destroys toxins and develops flavour; some of the corn oil is broken down into mono- and di-glycerides, facilitating bonding, and dough formation.  The only difference is the use of white corn for Maseca™ (I will call it Nixtamal white), and yellow for Bob’s (Nixtamal yellow; bonus: Bob’s is organic.)

The PAN™ white flour was created for arepa dough, a staple in Venezuela and Colombia; the yellow is the same, just using yellow corn.  Although they are not nixtamalized, they are pre-cooked, and listed as also useful for gorditas and other Mexican products.  I decided to test these four pre-cooked flours:

precooked corn flour samples My Slice of Meico

I prepared dough from each type with one cup of flour, adding the amount of water and following the instructions as indicated on each package.  I also prepared an extra batch mixing half a cup from each of the white flours, and another doing the same with the yellow flours. The PAN flours called for more water than the nixtamal, which is not surprising since they are finer, with more surface area to wet.  While mixing the water and flour, it was harder to incorporate the nixtamal samples.  For all of them, it seemed at first like the water was not going to be enough, but the instructions directed to kneed for 2-3 minutes, which was enough time to get the mixes to a rolling consistency.  The following photos illustrate the procedure for the half nixtamal/half PAN white mix:

The six samples were kept in a glass container with lid, to preserve moisture.  Samples 1 and 4 (100% nixtamal) were more compact and less sticky than the rest.  Samples 2 and 5 (100% PAN) were the easiest to form and absorbed water quickly, swelling the most, especially the yellow flour (sample 5), as can be appreciated in the photo.  Samples 3 and 6 (50% nixtamal-50% PAN) were somewhere in between, as expected:

All six corn dough samples My Slice of Mexico

Each sample was divided into four pieces, rolled into balls and pressed flat in between two plastic sheets, to form discs.  The three white flour samples were easy to press, and did not stick to the plastic sheets.  For the yellow pieces, the nixtamal dough, sample 4, was very easy to press, and had the best appearance and aroma of all six, but was stickier than the white samples, and had to be left slightly thicker; the mixed (sample 6) was stickier and had to be pressed even smaller and thicker; the yellow PAN, sample 5, was too soft to form thin discs, and was shaped into patties (hockey puck shape) by hand.  Below, discs from samples 1, thin (left) and 4, smaller and thicker (right):

The tortillas were cooked using an ungreased iron skillet, for about 2 minutes per side:

White PAN skillet My Slice of Mexico

The white tortillas were thin and easy to roll (left).  The yellow were thicker, but the aroma and texture were very nice:

The final test, of course, was tasting  a cooked sample from each batch:

  1. Nixtamal white – Thin and easy to roll.  The flavour was nothing special, just like packaged tortillas.
  2. PAN white – Thin and easy to roll. The best flavour of the white tortillas.
  3. 50-50 Nixtamal-PAN white – Thin and easy to roll. Nicer flavour than 1.
  4. Nixtamal yellow – Thicker and a little hard to roll.  The best flavour and aroma of all six samples.
  5. PAN yellow – Formed into hockey puck patties. Very fluffy and nice flavour and colour.
  6. 50-50 Nixtamal-PAN yellow – Thicker and not possible to roll.  Good flavour.

The whole prepping and cooking time was at least two hours, so for all the work, it seems like making tortillas instead of buying a package would be worth only in terms of flavour, so the winner in the tortilla category is sample 4, Bob’s Red Mill™ yellow nixtamal flour, and second place, for white tortillas, sample 2, PAN white.

gorditas yellow PAN My Slice of MexicoFor thicker shapes, for example gorditas (hockey puck shaped), the yellow PAN was very nice (photo, right); for quesadillas (folded) or sopes (thick and small discs), all samples except yellow PAN would be good.

For tamales, the flour is usually from white corn, and it is better to have a light batter, so probably the 50-50 white mix would be the best choice.

For arepas (not Mexican, but very yummy), the original white PAN is the way to go.

I am going to keep buying commercially made corn tortillas in general, just like millions of Mexicans do every day, and I will make them by hand only for very special occasions.  The rest of the results, and the chart, will come in handy when I call for “corn flour” in future posts; if I have missed any, let me know.  I hope that this information will allow every reader to identify exactly which flour I am using when baking, or cooking any of the other preparations mentioned above (sopes, tamales, and gorditas, oh my!)

50 thoughts on “Corn Flour and Masa 101

  1. Love this post!
    There is a supermarket here that carries vacuum sealed corn tortillas, but I prefer the flavor of homemade using Maseca (which is the only brand of nixtamal I can get here).
    Making 8 tortillas is not that much work, fortunately.


    1. Thank you, Stefan! Unfortunately Maseca is the brand that is single handedly ruining the diversity of artisan tortillas in Mexico; I wonder if the packaged ones you find over there are made from better corn. I read your comment from my “The secret of good corn tortillas” post; I hope you get to try making the masa and tortillas from dry corn (there is a link on this post to the Serious Eats’ recipe and article on how to do that.)

      Liked by 1 person

    1. I just found this blog because I was researching Tlayudas. I joist bought some at a local Mexican restaurant in Santa Monica (in Los Angeles County) called Samo’s Oaxaca. They sell pre-made Tlayudas from Oaxaca! 5 for $5. I was told they can last a few weeks in fridge. I wasn’t sure how to use them
      (or how to refresh/heat them up) as they are kind of dry (as verified by my friend from El Salvador whose husband is Mexican).

      Liked by 1 person

  2. Hello, such a great post. I missed it though, so is masa harina a whole grain that keeps the endosperm or is it degerminated? Did you have any real difference between corn flour and masa harina, since seems like the corn flour is healthier?


    1. “Corn flour” is a generic name, and it might refer to different products in different countries. Masa harina is the Mexican one used for tortillas, etc. and is a whole grain corn flour, in which the grain is soaked and cooked with calcium hydroxide, a process called Nixtamal, that softens the hull. I am not sure what you are calling “corn flour” in your second question.


      1. Thanks for your great response. You are right I should have been more clear. When I am referring to corn flour, I am referring to whole grain corn that has been grounded up into a flour. I understand the mass has been treated and processed differently than this, but what I am unsure of is if masa is a whole grain since it does not have the whole grain label on it and I have found conflicting comments on if the masa still has its endosperm or if it is also degerminated. Does my question make more sense now? Thank you for your quick response!


      2. Masa harina loses the hull and bran (the outside) during the nixtamal process, so technically cannot be labelled as whole grain, but it does start whole. The endosperm is the “pulp” inside, where the starch is, so yes, all corn flours have that, and for masa harina, the germ is still in. The only corn flour without germ is what we call “corn starch” in the US and Canada, that very fine white powder for thickening sauces.
        Now, back to your question, masa harina would have less fibre than ground whole grain corn (although starch stabilizes due to nixtamalization, contributing with a little fibre); I would not say it is less healthy or less nutritious, though, because they both have the germ, and during the nixtamal process, some toxins are destroyed or degraded (specifically mycotoxins, fungal metabolites). In addition, the calcium content increases from the calcium hydroxide, hence aiding iron availability.
        Was this helpful? Let me know if you have more questions.


      3. Okay, and yes this is super helpful and insightful. Thanks for clearing it up. One last follow up question.

        So then since the germ is still in the masa harina you would say this is competent different from say the difference between whole grain bread and all purpose flour? Since there the process degerminates the whole grain to make the all purpose flour and that’s when the nutrition is lost. Here, unless the manufacturers degerminate the masa then it is probably closer to a whole grain than an all purpose flour or say corn starch. And it seems like you haven’t heard of companies in the US that actually take the extra step of degerminating. I am also using the popular brand maseca which is made by gruma. Thanks again! Promise this is the last one.


      4. Yes, so all purpose wheat flour would be a little like corn starch, and masa harina is still nutritious, compared to those, and only with less fibre than whole corn grain flour. I had never heard of de-germinated corn flour, other than corn starch, yikes!
        Thank you for your comments, and ask away as much as you want!


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