The finely ground and sifted meal of any of various edible grains.
Flour contains a high proportion of starches, which are a subset of complex carbohydrates also known as polysaccharides. The kinds of flour used in cooking include all-purpose flour, self-raising flour, and cake flour including bleached flour. The higher the protein content the harder and stronger the flour and will produce crusty or chewy breads. The lower the protein the softer the flour for better cakes, cookies, and pie crusts.
Flour that does not have a leavening agent is called plain or all-purpose flour. It is appropriate for most bread and pizza bases. Some cookies are also prepared using this type of flour. Bread flour is high in gluten protein, with 12.5-14% protein compared to 10-12% protein in all-purpose flour. The increased protein binds to the flour to entrap carbon dioxide released by the yeast fermentation process, resulting in a stronger rise.
All purpose flour is usually used when a recipe just calls for ‘flour’.