The grain wheat or ‘kernels’ are surrounded by a “pericarp” and contain the bulk powder and the ’embryo’ or germ. If you proceed only to grinding of the grain you have the ‘whole wheat’that is gray and is working to get the dough and wholemeal bread.
By sifting, it is eliminated the bran and bran flouro obtainig the white flour, and after sifting and regrinding the white flour we will have flour of types and different strengths, the quality of flour, or fine flour, is what’s coming from innermost part of the grain, white, impalpable, being often marked by numbers (double 0, 0, 1.2..) which indicate their purity.
More flour is refined and more decreases in protein contents in relation to starch. The “whole wheat” instead is obtained with a gap from 50 to 10%, or 15% protein and 79.20% starch, and flour with a gap of 25% will have the 1.23% of proteine against `86.11% starch.