Nixtamalisation was discovered independently in Mesoamerica approximately 3,500 years ago and spread throughout the Americas with corn cultivation. When corn was introduced to Europe in the 16th century without the knowledge of nixtamalisation, populations dependent on it as a dietary staple developed pellagra (niacin deficiency) — the disease that devastated parts of southern Europe for centuries. The process that prevented this in America was not understood or transmitted.
Nixtamalisation — the process of soaking and cooking dried corn in an alkaline solution (traditionally water with cal, calcium hydroxide/slaked lime) — is one of the most significant food processing discoveries in human history. The alkaline treatment transforms dried corn from a nutritionally incomplete food into a complete one: it releases niacin (vitamin B3) that is biologically unavailable in untreated corn, significantly increases the bioavailability of amino acids, and transforms the corn's flavour and texture in ways that make tortillas, tamales, and pozole possible.
- **The cal (calcium hydroxide):** A strong alkali that raises the pH of the cooking water to 11–12. The alkaline environment breaks down the corn's pericarp (outer hull) and releases bound niacin. - **The cooking:** Dried corn + cal + water — brought to a simmer, cooked 30–60 minutes, then rested overnight. The extended rest allows the alkaline water to fully penetrate each kernel. - **Washing:** The nixtamal (treated corn) is rinsed thoroughly the next day — removing the outer hull and excess calcium. - **The resulting masa:** Ground nixtamal produces masa — the transformation of the corn's starch structure during nixtamalisation allows the masa to form a cohesive dough that untreated corn flour cannot. The characteristic smell of fresh masa is entirely the product of nixtamalisation.
Mexico: The Cookbook