Freeze-drying offers the advantage of mild drying. However, a drawback is the long drying time. One way to reduce the drying time is to use dynamic freeze-drying. Here, the heat transfer to the product is improved and the forming dry layer is permanently removed. Thus, the heat and mass transfer resistance is reduced and it is dried in the vicinity of the ice crystals. This results in an increase of the drying rate, since it can be dried in the first drying section.