is the most common milling process employed in modern brewhouses. Its opposite is wet milling, during which the grist is moistened before it reaches the mill. See milling, wet milling. Dry milling relies on a roller mill of varying degrees of complexity with two, four, five, or six rollers and complex arrays of vibrating screens to crush the grist kernels—malted and/or unmalted—into smaller particles and to separate grits, husks with attached grits, and flour in preparation for mashing and lautering. See roller mill. In complex roller mills, the grist is passed sequentially and sometimes repeatedly through consecutive pairs of rollers with different gaps until the desired combination of fine and coarse grinds is achieved. The advantage of dry versus wet milling is its simplicity. Its disadvantage is that it generates dust, with the attendant danger of explosive ignition by sparks.