Re: Why does flour not dissolve in water?

Flour is made up mainly of protein and starch granules. Both of these are difficult to "whet" -- have poor wettability, so water does not readily mix without some prior preparation - the water will just "run off" of the flour. With time and kneading, one can slowly work the water into the flour to create a dough. With heating the starch granules will break down. The kneading itself also changes the structure of the protein, mainly gluten, and gives the dough a structure which will permit it to trap gas bubbles and stretch.