When saving fruit seeds to plant in the next growing season, it's important to take a couple things into consideration. Seeds from hybrid plants are not worth preserving because most hybrids are infertile. Additionally, seeds from plants that appear to be infected with a disease, however minor, should never be saved. Diseases can remain in the seed and severely infect the new plant. Drying fruit seeds is a fairly simple process, and can save time and money the following growing season.
Wait for the fruit to fully mature before picking it off the plant and removing the seeds. Usually when a plant is fully mature, the flowers fade and dry out and the fruit falls from its branch or vine when touched. Mature seeds will have darkened from white to tan or light brown to dark brown.
Remove the seeds from the fruit. Slice it open and scrape them out of the center. In some cases (such as with melons), the seeds will be tangled in a gooey mass. If this is the case, use a melon baller to remove the seed masses. If the seed isn't easily removed (such as with berries), lightly crush the entire fruit.
Place the seeds, seed masses or crushed fruits into a bowl and cover with warm water. Allow the bowl to sit in a cool, dry place for two to four days, stirring daily. Because fruit seeds often have flesh still attached to them, this method kills the germs and detaches the seeds from the fruit through fermentation.
Scoop the pulp, bad seeds and mold from the top of the water; discard. The good fruit seeds will sink to the bottom of the bowl during the fermentation process. Remove those seeds and spread them on a layer of paper towels to dry.
Place the seeds in airtight glass jars once they are completely dry. Label the jars with the type of seed as well as the date and place them in the freezer for two days. The cold temperatures will kill any remaining germs and pests on the seeds.
Store the jarred seeds in a cool, dry place until planting season.