Processing Methods

To save seed there are only three simple processes to know. Once you have an understanding of each of the processes, you can save almost any seed. For specific processing requirements for individual plants refer to an seed saving resource that describes each species in detail.

Dry Seed Processing

Seed is left on the plant to ripen and dry, this is normally well past the usual picking/eating stage. The seeds are harvested, usually by cutting the whole seed pod/flower head or even the whole stalk off of the plant. The seed is then separated from the parent plant; threshing, lightly crushing and hand picking are used depending on the size and type of seed. Fully dry seeds normally separate very easily. The seed is then cleaned from any remaining chaff by sieving, winnowing or using a gold panning action.
Used for; legumes, grains, lettuce, brassicas, onions, beets, carrots, celery etc

Wet Seed Processing

Involves removing the seed from the overripe fruit, rinsing clean of debris, and then drying. A jar of water can be used to separate seed from debris – seeds usually sink and debris usually floats. Drying the seed quickly and completely after wet processing is very important.
Used for; soft fleshed fruits, melons, peppers, eggplant, tomatillo, pumpkin etc

Fermentation Processing

Similar to wet seed processing, but the seeds and their juices (as in tomato and sometimes melons and cucumbers) are mixed with a little water and allowed to ferment for a few days. The fermentation process breaks down germination inhibitors such as the gel-sack that surrounds tomato seeds. When a layer of mold has formed on top of the water and the seeds sink, the fermentation is complete. Then simply add more water, swish it around, then decant the mold and pulp. This process is repeated several times until all of the pulp, bad seeds (floaters) and mold is removed, then drain the water from the good seeds seeds (sinkers) and set them out on a plate, screen, or paper towel to dry. Once the seeds are thoroughly dry, place them in a moisture-proof container, label and store them for the future.

Used for; tomatoes, cucumbers, pomegranate, some melons and any seeds that have a gel sack surrounding them after washing

CHB Seed Library occasionally runs Seed Saving Workshops.