Winnowing

Manufacturers separate the shells from the nibs through a process called winnowing. It is carried out by a series of sieves combined with airflow. By FDA standards, chocolate liquor may contain no more than 1.75 percent cocoa shell. Regulations aside, it is important to remove as much of the shell as possible, as it can contribute off flavors to the chocolate, and the fat it contains has a softening effect on cocoa butter.