Leavening is added to bread dough to make it rise before and during cooking so that the bread becomes lighter and fluffier. Sometimes baking powder or commercial yeast is used for this. Other breads use starters, which are simple mixtures of flour and water that grow wild yeast. Additional flour and water are added to the starter to continue the strain. Unleavened breads, on the other hand, do not use leavening and remain flat when cooked. They are a featured food in cultures around the world.
Matzo is a bread associated with the Jewish Passover and was the type of bread used at the Last Supper by Jesus. The bread is made of flour and water, spread thin and pricked with holes before baking. It is a crisp bread that can be broken into serving pieces. Ground up, it becomes matzo meal, which is used in various ways, including matzo ball soup or as a substitute for flour.
Pita bread is a flat, round bread closely associated with Middle Eastern cuisine. There are leavened and unleavened variations. When cut in half, each side of a pita can be split open, creating a pocket that holds food. Pita pockets are used for both cold salad items and heated ingredients. They are also cut into triangles, cooked until crisp and used for dipping hummus, a dish made from garbanzo beans, garlic and olive oil.
Tortillas are Mexican flatbreads made of flour or corn and eaten with spicy meat mixtures, beans and cheese. They function as a holder for eating by hand, as with tacos, or are wrapped around ingredients and smothered in sauces or gravies, as with enchiladas. Tortillas are made with flour or with corn that is ground and mixed with water then flattened and cooked on a griddle.
Crepes are thin, unleavened pancakes that appear most often in sweet dishes, but there are savoury crepe recipes as well. In some places, food stands that sell crepes are abundant and are called creperies. Brittany in France has a large number of creperies.