Posole comes from the Nahuatl word pozoll. This traditional Mexican soup has been known in Mesoamerica since the pre Columbian era, when maize was a sacred plant to the Aztecs and other peoples of the Americas. The soup’s primary ingredient is hominy, a food made from dried maize kernels treated with an alkali in a process called nixtamalization (nextamalli is the Nahuatl work for hominy). The Maya created the caustic powder by toasting freshwater shells over a fire for several hours, and others used limestone to make slaked lime for steeping the kernels. Since ancient times hominy has been finely ground to make masa (Spanish for dough), which, when dried and powdered, was mixed with water to make masa harina, the stuff of which tortillas are made. Posole is completely pre Hispanic in origin and was described by Franciscan friar and missionary priest Bernadino de Sahagun in the 16th century Florentine Codex.
Today the soup is common throughout Mexico and may be an everyday dish or a treat reserved for special occasions, such as New Year’s Eve, Christmas, Mexican Independence Day or even birthdays. It comes in three colors, rojo (red), blanco (white) and verde (green), the colors of the Mexican flag. The white version is thought to be closest to the original recipe, the red includes chiles like guajillo, ancho or piquin, and the green may call for tomatillos, cilantro and jalapenos. Posole is traditionally accompanied by condiments like diced onions, shredded lettuce or cabbage, sliced radishes, avocado, limes, cilantro or chiles.
Chicken is sometimes used in posole, but more often pork is the protein of choice. And the reason is startling; research by Mexican authorities indicates that the meat used in ancient posole was human flesh. Prisoners were killed in ritual sacrifice (usually by removing their still beating hearts) and their bodies were then prepared for a long simmer. The soup was consumed by the entire community in an act of religious communion. When cannibalism was banned after the Conquest, pork replaced people because “it tasted very similar” to human flesh, according to Bernardino de Sahagun.