Bread is a staple food prepared from a dough of flour and water, usually by baking. Throughout recorded history it has been popular around the world and is one of the oldest artificial foods, having been of importance since the dawn of agriculture.
There are many combinations and proportions of types of flour and other ingredients, and also of different traditional recipes and modes of preparation of bread. As a result, there are wide varieties of types, shapes, sizes, and textures of breads in various regions. Bread may be leavened by one of many different processes, ranging from reliance on naturally occurring microbes (so-called "sourdough" recipes) to addition of chemicals or industrially produced yeast to high-pressure artificial aeration methods during preparation or baking. However, some products are cooked before they can leaven, sometimes for traditional or religious reasons. Many non-cereal ingredients may be included, ranging from fruits and nuts to various fats. Commercial bread in particular commonly contains additives, some of them non-nutritive, to improve flavor, texture, color, shelf life, or ease of manufacturing.
Depending on local custom and convenience, bread may be served in various forms at any meal of the day. It also is eaten as a snack, or used as an ingredient in other culinary preparations, such as fried items coated in crumbs to prevent sticking, or the bland main component of a bread pudding, or stuffings designed to fill cavities or retain juices that otherwise might drip away.
Partly because of its importance as a basic foodstuff, bread has a social and emotional significance beyond its importance in nutrition; it plays essential roles in religious rituals and secular culture. Its prominence in daily life is reflected in language, where it appears in proverbs, colloquial expressions ("He stole the bread from my mouth"), in prayer ("Give us this day our daily bread") and even in the etymology of words, such as "companion" and "company" (from Latin com "with" + panis "bread").
Bread is the staple food of the Middle East, North Africa, Europe, and in European-derived cultures such as those in the Americas, Australia, and Southern Africa, in contrast to East Asia where rice is the staple. Bread is usually made from a wheat-flour dough that is cultured with yeast, allowed to rise, and finally baked in an oven. The addition of yeast to the bread explains the air pockets commonly found in bread. Owing to its high levels of gluten (which give the dough sponginess and elasticity), common wheat (also known as bread wheat) is the most common grain used for the preparation of bread.
Bread is also made from the flour of other wheat species (including durum, spelt and emmer), rye, barley, maize (corn), and oats, usually, but not always, in combination with wheat flour. Spelt bread (Dinkelbrot) continues to be widely consumed in Germany, and emmer bread was a staple food in ancient Egypt. Canadian bread is known for its heartier consistency due to high protein levels in Canadian flour.