A crop with a Mexican origin
Maize, the plant most English speakers call corn, was domesticated in what is now Mexico from a wild grass called teosinte. Researchers generally place this long process in southern Mexico many thousands of years ago, and the exact timing and details are still studied. What is clear is that people shaped the plant over generations, selecting for larger ears and more kernels, until it became the crop that now feeds people across the world.
In Mexico it is more than an ingredient. It is a farmed, seed-saved, regionally varied crop, and that diversity affects what ends up on the plate.
Landraces and heirloom maize
Mexican farmers have developed many locally adapted types of maize, often called landraces or criollo corn. Specialists recognize dozens of distinct races, and within each race there are many local strains adapted to altitude, rainfall and soil. These are sometimes grouped with the term heirloom maize, although in Mexico they are simply the corn that families have always planted.
The differences are practical. Some varieties tolerate dry conditions, some mature quickly at high altitude, and some are bred for a particular dish. One well-known example is the large-kerneled cacahuazintle, traditionally used for pozole. Others are grown mainly for tortillas, for tamales, for toasting, or for eating as fresh ears.
Colors
Maize comes in more than yellow. Kernels may be white, yellow, red, purple-blue, black-looking or speckled, and sometimes several colors appear on one ear. The pigments differ, and the blue and purple types contain anthocyanins, the same group of pigments found in some berries. Color influences appearance and often flavor and aroma, though the effect is subtle and depends on the variety, the growing season and the way it is processed.
Blue corn is the best known colored type, and its tortillas have a slightly different, nuttier taste than white corn tortillas. Cooks also make use of red, yellow and speckled types. You may see variations in color from one batch to another because grain from native varieties is naturally less uniform than that from commercial hybrids.
How farming shapes flavor
Several factors affect how maize tastes and cooks:
- Variety. Starch content, kernel hardness and oil determine whether a corn makes a soft, pliable dough or a coarse, chewy one.
- Growing conditions. Altitude, soil and weather influence kernel size and sweetness. Much of Mexican maize is rain-fed.
- Harvest and drying. Corn may be eaten fresh, as elote, or left to dry on the plant. Dried corn can be stored for months, which is why it became a staple.
- Processing. Whether and how kernels are treated with lime before grinding affects flavor and texture. That kitchen-side process is covered in its own article.
Producers and cooks often say that native corn has a stronger flavor and aroma than commercial grain, and many chefs and farmers value that. Because tastes are subjective and results depend on the cook, it is more accurate to say that people often prefer it than to say it is objectively better.
The milpa and companion crops
Traditionally, maize is planted in a field together with beans and squash, a system known as the milpa. Beans climb the stalks and squash covers the ground. This arrangement is common in many farming communities and gives a varied, balanced harvest. The milpa system also explains why corn, beans and squash appear together so often in meals. Other plants, such as wild greens and chiles, may grow in or around the field.
Seed saving and diversity
Many farmers save seed from their best ears for planting the following year, which keeps local varieties adapted to their land. Seeds are also exchanged in markets and between communities. This tradition is a main reason Mexico still holds such a broad range of maize types.
There are ongoing concerns about how diversity is maintained. Commercial hybrid seed, changing climate, migration away from farming and cross-pollination from introduced varieties all affect local strains. Conservation groups, seed banks and farmers work to protect native varieties, and the topic is debated, including the question of genetically modified corn. This article does not take a position, and readers who want to know more should consult reliable agricultural and scientific sources.
Corn beyond the tortilla
Corn appears in a long list of dishes: tortillas and tamales, atoles and other drinks, pozole, fresh ears served with lime and chile, toasted kernels, and corn silk teas in some regions. A corn fungus that grows on ears, called huitlacoche, is also eaten as a delicacy. In each case the choice of corn matters. A variety that makes good pozole may be unsuited to tortillas, and the best tortilla corn may not be right for atole.
Buying native corn products
If you want to try tortillas, masa or dried kernels from specific native varieties, look for sellers that name the variety and its region. The labels “heirloom” and “native” have no single legal definition, so ask about sourcing. Store dried corn in a sealed container in a cool, dry place and keep it away from moisture, since damp grain can grow mold.