What corn-based dough is used to make tamales?

The corn-based dough used to make tamales is masa, also called masa de maíz.

Masa is made by grinding nixtamalized corn: dried maize is cooked and soaked in an alkaline solution, traditionally lime or wood ash, then rinsed and ground. This process softens the kernels, loosens their hulls, improves the dough’s binding properties, and makes the niacin in corn more available for absorption. The resulting fresh dough can be mixed with water or broth, fat, salt, and sometimes baking powder before being shaped around a filling.

For tamales, masa is spread inside corn husks or banana leaves, filled with ingredients such as meat, beans, cheese, vegetables, or fruit, and steamed until firm. Tamales are a broad Mesoamerican tradition with many regional forms, so their fillings, wrappers, seasonings, and textures vary widely.

Masa harina is not the same thing as fresh masa: it is the dried, powdered form made from nixtamalized corn and must be reconstituted with liquid. Cornmeal and polenta are different products and generally have not undergone nixtamalization, so they do not provide the same texture or nutritional changes. Some regional tamales use other grains or tubers, but the classic corn dough is masa.