Vessels, usually of baluster or cylindrical shape and intended for serving dry, ground mustard flour; used especially for vessels that were historically part of a set of casters at table. A mustard caster may have a pierced, domed lid or it may be a blind caster, meaning the lid is not pierced or is blocked with an interior sleeve to prevent moisture in the air from causing the powdered mustard to clump. For vessels used to contain and serve prepared, wet mustard, usually having a cover or lid, use "mustard pots."
