How to Screen and Winnow Seeds
After the Harvest, Low-Tech Tools Simplify Seed Saving
Here are a few devices for separating seeds from debris and chaff:
• Pillowcase or Cloth Sack - Perhaps the most common method of hand threshing. Place seed pods in the sack and thrash (“thresh”) it against a hard surface to break the seeds from their coverings.
• Boards - Place harvested seed pods between two boards and apply gentle pressure to crack open the pods. Take care not to press so hard you split the seeds.
• Screens or Strainers - Screens with meshes of varying sizes provide a quick way to separate debris from seeds. Even using a single screen is a vast improvement over hand picking. Screens work especially well for seeds (such as lettuce) that do not have pods. A set of graduated screens will cut out about 80 percent of the hand work. You can build screens yourself or order seed cleaning screens from sources like Horizon Herbs.
• Wind Power - Outside on a breezy day, drop seed from one container into another and let the wind blow away the unwanted chaff.
• Electric Fan - While wind can be fickle and blow your chaff in unexpected directions, a fan set on low will produce a steady stream of air for winnowing.
• Gravity - This works well for round seeds. Use gravity to help roll seeds down a newspaper into a container. The heavier seeds roll down, while the chaff remains behind.
Below, seed saver and year-round gardener, Celt Schira, demonstrates how she uses screens, the wind, and gravity to help separate the chaff from garden sage seeds:
Slideshow: Screening and Winnowing Seeds
Seed saver, Celt Schira, writes about gardening and self-sufficiency on her blog: Celt’s Garden.