This recipe is straight out of King Arthur Flour's Whole Grain Baking. The freshly-ground flour made a huge difference in taste.
While processed white flour can be stored indefinitely, the same is not true of whole wheat flour. The oils in it turn rancid and impart a bitterness to the taste. (Whole wheat flours from good companies have a 'Best if used by' date stamped on the package.)
All my research however shows that the best flour is that which was wheat just one or two days ago, and this recipe proves it, I think.