Scoring

Many loaves of bread are scored with a razor blade before baking. Professionals use one with a little handle called a lame (French for blade), but a single-edged razor blade works well. The purpose of scoring is not only decorative: It allows the bread to expand and prevents cracking in a random and unsightly way. If the dough is slightly underproofed—it hasn’t quite doubled in volume—it will quickly expand, especially in the cracks, soon after it goes into the oven. Bakers refer to this as “oven spring.”