The drying process begins with the delivery of fresh plants and the identification of the delivered plant parts. The plants must fulfil certain quality criteria:

• They must be free of dust and dirt.
• They must display no outward signs of disease or significant damage and there must be no withered or dead plant parts.
• There must be no rotting, pests or other changes which are not species-related.

A written evaluation bearing the name, date and signature of the inspector and any special observations is documented on the manufacturing form.

After release, the plants are weighed and, if they have not already been comminuted or chopped, are spread out evenly on the racks in the drug house. These racks are made of fine silk material mounted on wooden frames. Silk is particularly suitable for drying because it does not absorb moisture, does not swell and is particularly permeable to air.