Flour comes from the endosperm part of the wheat kernel, so millers must remove the endosperm from the bran. If you've ever seen tiny red specks in your flour, they're small pieces of bran from red wheat, and whole wheat flour is designed to have bran in it. With white wheat, the bran is less noticeable. More of the kernel can be used, which makes white wheat also more economical. White wheat has grown in popularity worldwide, and is especially popular in Indonesia, Iran and Iraq.
Hard wheats are higher in protein than soft wheats.
The higher the protein, the stronger the gluten - the substance that gives dough the elasticity it needs to trap gas produced by fermenting yeast, causing the dough to rise. Hard wheats are excellent for bread because bread needs that tougher gluten to make it rise. Soft wheats are ideal for products such as cookies and crackers. For the baker, it is the composition of that endosperm - protein quantity and quality, how the dough handles and the bread bakes. It can take up to 10 years to fully test and develop a new wheat variety and get it out in farmers' fields.