Tea sorting involves three main stages of cleaning : after plucking, during sorting and during packaging. There are various machines and meshes involved in the process of sorting. Besides these, moisture and temperature control also needs to be taken into consideration in the context of tea leaves, dust, and bacterial contamination. When the leaf brought from the field is dry, there is little increase in bacterial growth.
But if the leaf brought to the factory is wet, as it happens during the rains, the conditions become favorable for bacterial growth. The food material required for bacterial growth is drawn from the leaf itself. The bacterial growth is checked with the removal of surface moisture.