Spoon the seeds and gel out of ripened tomatoes before preparing the fruit to eat. Use tomatoes from the healthiest plants in your crop so the future plants will also be robust.
Place some water, seeds, and gel in a glass jar. Stir the seeds twice a day. Fermentation will occur and the seeds will sink in five days to the bottom of the glass jar.
Remove the liquid from the jar and rinse the seeds off. Place the seeds on paper towels at room temperature to dry.
Store the dry seeds in an airtight glass jar in a refrigerator or a location with a temperature of 32 to 41 degrees F. Use 2 tbsp. of a desiccant, such as powederd milk, wrapped in a tissue to absorb any extra moisture that the seeds release while stored in the jar.
Leave some peppers on the healthiest plant in your crop until they are ripe. The peppers will begin to wrinkle when they are ready for the seeds to be removed.
Cut open the ripe peppers, and remove the seeds.
Lay the seeds out on paper towels. Leave the seeds out to dry before storing for next season.
Place dried seeds in a lid covered glass container for storage. Put a desiccant in the jar to remove any moisture from the jar that the seeds may expel while in storage. Put 2 tbsp. of dried milk in a tissue for a convenient desiccant to place in the jar.