This is a vibratory sifter for screening finished chocolate or refined liquor to remove oversized particles. This process is done after refining and before tempering.
Chocolate producers often screen products prior to tempering to minimize the presence of unrefined particles such as coarse sugar, germ stems, bean debris, and other foreign materials. In the case of germ stems, the chocolate can be over-refined in an attempt to grind the hard, bitter stems.