Seed processing is concerned with purification of the seedlot (removal of debris), dewinging and removal of non-viable seed. Seed extracted from the cones during cone processing is moved to the processing area, where it travels through equipment specially designed to sort seed and inert material by size, shape or density. During processing the seedlot identity is ensured through labeling bags of seed or containers inside and out. Quality assessments are performed at all stages of seed processing. The seed processing equipment at the TSC is adaptable to a wide variety of tree species and seedlot sizes.

Seed material is first cleaned by screening to remove debris that could abrade the seed, contaminate it with fungi or add moisture to the seed. This screening also greatly reduces the volume of material we need to manage. The next step is dewinging and all species, except western red cedar, yellow cedar and most hardwoods, are dewinged. The wings are removed in a rotary dewinger and this process is performed dry or wet depending on species biology. Spruce and pine are wet dewinged and the remaining dewinged species are dry dewinged. A liquid separation bath is used with wet dewinged species to remove resin particles, damaged seed and other debris that is heavier than water. Seed is then dried in a continuous-flow tray drier to 4.0 - 9.9% moisture content. The seedlot may be cleaned further by screening or through the use of other specialized equipment. The final separation removes non-viable seed through the use of various specific gravity cleaners. The final stage of cleaning is a fine-scale separation that will continue until the maximum volume of potentially viable seed and a purity of 97% or more is achieved for the seedlot. The cleaned portions are then thoroughly mixed to form one homogeneous seedlot ready for sampling, testing, packaging and storage.

Clients may wish to ship extracted or partially processed seed to the TSC for further processing.