A rotary drum (302) for use within a vacuum chamber (212) in a vacuum freeze-dryer (204) for the bulkware production of freeze-dried particles is provided. The drum (302) is in open communication with the vacuum chamber (212) and comprises a main section (304) terminated by a front plate (306) and a rear plate (308), the rear plate (308) is adapted for connection with a rotary supporting shaft (312) for rotary support of the drum (302), and the rear plate (308) is permeable for sublimation vapor from freeze-drying the particles.