Flowchart of Nixtamalization process.svg
The process of making masa from maize
Associated national cuisineMexico
Main ingredientsHominy
Cookbook: Masa  Media: Masa

Masa (English: ə/; Spanish pronunciation: [ˈmasa]) or masa harina is a maize (corn) flour or dough that has been soaked and cooked in an alkaline solution in the nixtamalization process. It is used for making corn tortillas, tamales, pupusas, and many other Latin American dishes. The full name is masa de maíz; the dried and powdered form is called masa harina, masa de harina, and sometimes Maseca, the name of a leading commercial brand. It is reconstituted with water before use.[1]

In Spanish masa harina translates to 'dough flour' and can refer to many types of dough in addition to the specific subject of this article.


Field corn (maize) grain is dried and then treated by soaking and cooking the mature (hard) grain in a diluted solution of slaked lime (calcium hydroxide) or wood ash, a process termed nixtamalization, and which produces hominy, which is ground to create masa.

Lime and ash are highly alkaline: the alkalinity helps the dissolution of hemicellulose, the major glue-like component of the maize cell walls, and loosens the hulls from the kernels and softens the corn. Some of the corn oil is broken down into emulsifying agents (monoglycerides and diglycerides), while bonding of the corn proteins to each other is also facilitated. The divalent calcium in lime acts as a cross-linking agent for protein and polysaccharide acidic side chains.[2] The soaked maize is washed, and then ground into masa. When fresh masa is dried and powdered, it becomes masa seca or masa harina.

The chemical changes in masa allow dough formation, and also allows the nutrient niacin to be absorbed by the digestive tract. By contrast, untreated cornmeal is unable to form a dough on the addition of water, and a diet heavily reliant on its consumption is a risk factor for pellagra.[3]

Other Languages
français: Masa (maïs)
日本語: マサ
português: Massa de milho
українська: Маса (їжа)