The scoop: Made from ground, lime-soaked corn kernels, masa (which means "dough" in Spanish) is one of the cornerstones of Latin and South American cuisines. Masa harina is dried, powdered masa, which can either be reconstituted with water or used as a flour. Both masa and masa harina have a sweet corn flavor and smooth texture that's less grainy than polenta or cornmeal.
How it's used: Masa is the main (and sometimes only) ingredient in corn tortillas, tamales, empanadas, and fritter-like sopes, arepas, and pupusas. Add water, and masa harina can do the same things; it can also be used to make batters, dust fried foods, and replace part of the flour in muffin, pancake, dumpling, and bread recipes.
Shopping and storage: Fresh masa can sometimes be found in the refrigerated section of Latin markets or bought from tortilla factories. Masa harina is widely available in the baking or Latin American section of supermarkets (Maseca is a common brand). Store masa harina in the refrigerator or freezer to prevent it from turning rancid.
Pupusas with Curtido (pictured)