wheat flour from which a large part of the starch has been removed, thus increasing the proportion of gluten.
Pastry flour contains more starch and less gluten than bread flour, therefore makes a lighter, more tender cake.
Soft wheat has less protein, therefore less gluten, than the wheat used for all-purpose flour and a lot less than bread flour.
Bread flour has a higher gluten content then all-purpose flour and is used specifically for baking breads.
Its other food uses are breakfast cereals, bread flour and pearled barley as a soup thickener.