Nixtamalization is a process which involves soaking a grain in a highly alkaline solution to loosen the outer hull, which is known as the pericarp. When grains are nixtamalized, the solution frees up available nutrients and proteins in the grain, making it accessible to consumers and thereby raising the nutritional value of the grain. The process also makes grains easier to grind and handle. The most commonly nixtamalized grain is probably corn; as a result, some people mistakenly believe that “nixtamalization” refers to the treatment of corn specifically.
As you might guess from the name, which is Nahuatl in origin, nixtamalization originated in Latin America. Archaeologists are not exactly sure when nixtamalization was discovered, but it is safe to say that it has been practiced since at least 2,000 years BCE, and it may be much older. The first solid remains of nixtamalization date back to around 1,500 BCE, and they were discovered in Guatemala.
The discovery of nixtamalization probably revolutionized American society. Corn is one of the “three sisters,” the crops which comprised the majority of cultivated crops for Americans until the arrival of Europeans; the other two were beans and squash. Unfortunately, untreated corn is nutritionally lacking, and a steady diet of non-nixtamalized corn can actually cause a condition known as pellagra due to vitamin deficiencies. By learning how to treat the corn, people greatly improved their diets and laid the groundwork for centuries of elaborate cuisine, because without nixtamalization there would be no tortillas, tamales, and many other beloved Latin American dishes.
There are several stages in the nixtamalization process. The first stage involves soaking dried corn with a lime solution, often with ashes mixed in. In Latin America, many people call lime “cal,” as a shorthand for “calcium oxide.” The grain is then cooked, allowed to steep, drained, and rinsed, sometimes multiple times. Once the rinsing is complete, the grain can be ground to make masa, which can be either used fresh or allowed to dry into corn flour.
In some regional Latin American cuisines, cal is also used in cooking, where it frees up dietary nutrients for consumers. Consumers who want to nixtamalize their own grain can find the necessary supplies at any Latin American grocery; for those not so inclined, most groceries sell both fresh and dried masa. If you happen to live near a tortilla factory, this is also a good source for fresh masa.