Corn masa is dough made from nixtamalized corn, corn kernels soaked and cooked in an alkaline solution (traditionally limewater) that softens the kernel, removes the hull, and improves the corn's nutritional availability. Fresh masa is ground straight from wet nixtamalized corn, while masa harina is the same dough dried and reground into a shelf-stable flour that is rehydrated with water before use; the two are not identical, though 'corn masa' is often used loosely for either. Masa is the base for tortillas, tamales, and tostadas across Mexican and Central American cooking, with a distinctive, slightly tangy corn flavor different from plain cornmeal.