What is the process called where corn is soaked in an alkaline solution to make hominy?

The process of soaking corn in an alkaline solution to make hominy is called nixtamalization. The corn is typically cooked and steeped in limewater made with calcium hydroxide, though wood ash or other alkaline materials may also be used.

During nixtamalization, the alkaline solution loosens and removes the corn’s outer hull, or pericarp, while softening the kernel and changing its chemistry. The treated corn, called nixtamal, can be eaten whole as hominy or ground into masa. Masa is the foundation for foods such as corn tortillas, tamales, and many other Mesoamerican dishes.

The process was developed in ancient Mesoamerica, where maize was a dietary staple. It has an important nutritional benefit: alkaline treatment makes niacin more available to the body and improves the availability of tryptophan, helping protect people who rely heavily on maize from pellagra, a niacin-deficiency disease.

Nixtamalization is not the same as parboiling, malting, or fermentation. Those processes use different methods and produce different chemical or biological changes. The word comes from Nahuatl terms associated with lime or ash and cooked corn, and the process remains central to Mexican and Central American foodways.