During the milling process, the husk is separated from the grain, which is broken into smaller pieces until flour is obtained. A typical mill consists of at least two rollers: one fixed and one rotating. The dry and brittle malt is crushed as it passes between them. If a finer product is required, the milling continues through additional pairs of rollers. The more roller pairs a mill has, the more finely the endosperm is fragmented; however, as the complexity of the mill increases, so does its purchase cost.