Buttermilk is a Flavorful Addition to Bread. It adds richness and just a hint of tanginess. It also contributes to an even-grained crumb. In the present formula, half the flour comes from whole grains, but that amount can be increased or decreased to suit the desires of the baker (remembering that dough hydration may need to be adjusted as the percentage of whole grains changes). While it can be difficult to source full-fat buttermilk, it’s worth looking for, as it makes a much tastier bread compared with its fat-free cousin. If time permits, reduce the dough temperature by 1 or 2 degrees and increase the bulk fermentation by up to 1 hour for even better flavor and slightly improved keeping quality.