Eggplant seed should not be saved from hybrid eggplants.
Hybrids are bred by crossing several parent plants. Trying to save and regrow the seeds of these eggplants is a lesson in futility. Most will be sterile and never germinate and those that do will not be true to the variety you saved them from. They will have reverted to one of the parent cultivars.
Open Pollinated plants are the best bet. Open Pollinated means that the seeds should ‘breed true’, although even this is not 100% guaranteed if they were grown where they could be pollinated by a hybrid variety. A separation of at least 300 feet from other varieties is recommended.
Eggplant seeds should be gathered from over ripe fruits, even bordering on rotten.
Eggplants as we eat them are sub ripe and seeds saved from ready to eat eggplants are immature, they will not germinate. The eggplant should be shriveled and sometimes even hard. The coloration should be a flat brown in standard eggplants, while lighter colored varieties will turn a golden yellow. The shiny luster we associate with ripe eggplants will be gone.
Collecting The Eggplant Seeds
Slice the overripe eggplant into cubes and separate the flesh from the seeds. A lot of the flesh will still be attached to the seeds, gently mashing up the pulpy seeds in a blender or even by hand will help separate more of the pulp. Pour this pulp and seed mix through a strainer with a fine enough mesh to catch the tiny eggplant seeds.
Agitate the pulp and seed mix to dislodge as many more seeds as possible, which will settle on the bottom. This process can be repeated multiple times as you will probably never get all the seeds, but as many as possible.
Storing the Seeds
Make certain the seeds are completely dry before storing them. Moisture easily leads to mildew which will destroy the seeds viability. Drying them off by placing them on absorbent paper towels or even coffee filters, followed by treatment with a hair dryer on a low setting works for me. Store them in a dry dark location for another 2 to 3 weeks before packaging them for winter storage.
Put the seeds in a airtight sealed jar [A zip lock plastic bag also works.] for winter storage. The reason for the jar is so you can monitor the humidity. If you notice any condensation on the inside of the jar – then there is unwanted moisture within the seeds. They could potentially grow mold or mildew.
Silica Gel works well for helping to keep stored seed dry. Silica gel is beads of amorphous silicon dioxide. Clear silica gel is packaged with many food and non food products and labeled ‘do not eat.’ Placing these in the jar with your seeds is advisable.
When properly stored eggplant seeds will be viable for up to 6 years.