Even if you don't know what masa harina is, you've almost certainly eaten it. This is the flour used to make corn tortillas and the filling for tamales. Pupusas, arepas, and sopes are all made with it, along with plenty of other favorite dishes. Masa harina is as central to the Mexican and South American pantry as chiles and dried beans. Do you ever cook with it?Masa harina is more than plain corn flour. Before being ground, the corn kernels for masa harina are soaked with limewater. Soaking in this alkaline solution actually changes the physical structure of the corn, making it softer and more pliable. This is why masa harina is able to form a pliable dough while cornmeal and corn flour will not. The process also gives masa harina and the foods in which it's used a distinctive taste and aroma.
As mentioned above, masa harina can be used to make a whole range of Mexican and South American foods from simple corn tortillas for tacos to stuffed arepas. It's even used to make a spiced porridge-like drink called atole.
You can find bags of masa harina at almost any grocery store or online. Stored somewhere dry and cool, the flour will keep for several months. Masa harina is naturally gluten-free, but check the packaging to make sure it wasn't processed at a facility that also processes wheat before using it to make gluten-free foods.