Mushroom trimming is the removal of the substrate-covered stem base and any damaged tissue from harvested fruiting bodies before packing or further processing, directly affecting yield and appearance.
In trade practice
Workers or automated cutters remove the lowest portion of the stem where growing medium adheres, cutting to a depth agreed in the supply specification. QA teams check trim depth and surface cleanliness during line inspections. Excessive trimming reduces net yield and raises cost per kilogram, while insufficient trimming causes contamination complaints. Trim waste is typically composted or returned to substrate production.
In a specification
A supply contract may specify the maximum permitted stem length after trimming and require that no visible substrate, mycelium mat or discoloured tissue remains on the finished piece.