Flour is a powder which is made by grinding cereal grains, beans, or other seeds or roots (like cassava). It is the main ingredient of bread, which is a staple food for many cultures, making the availability of adequate supplies of flour a major economic and political issue at various times throughout history. Wheat flour is one of the most important ingredients in European, North American, Middle Eastern, Indian and North African cultures, and is the defining ingredient in most of their styles of breads and pastries. While wheat is the most common base for flour, maize flour has been important in Mesoamerican cuisine since ancient times, and remains a staple throughout the Americas. Rye flour is an important constituent of bread in much of central Europe, and rice can also be used in flour, though this is relatively uncommon.
