A fresh tomato is one of the many treats of a summer garden, and if you enjoy your tomato crop you may want to harvest some of its seeds to save for next year's planting. While saving vegetable seeds is a relatively basic process, saving tomato seeds requires an extra step, and that is soaking the seeds. When you look at tomato seeds inside the tomato, you will see that they are coated with a light gel-type layer of film. To get the seeds ready for storage, they need to be soaked, cleaned and dried, which will remove that coating.
Select one of your best looking tomatoes to harvest the seeds from.
Cut the tomato in half, and scoop or squeeze out the seeds and the gel like substance that surrounds them into a glass jar or bowl.
Allow the container to sit on the counter, in a warm area, for at least five days. Stir the jar twice a day. During this process, the tomato content will begin to ferment. Healthy seeds will sink to the bottom of the jar, and seeds that are not viable will float to the top.
Scoop the matter that is at the top of the jar off and discard it, after five days.
Add 1/4 cup of water to the container. The good seeds will remain on the bottom, and the seeds that are not viable will float to the top.
Scoop the poor seeds and any debris off the top of the container.
Pour the water and the good seeds into a sieve and rinse them well.
Set the seeds out to dry on paper toweling or coffee filters. When they are dry, store them in paper envelopes.