Saving Tomato Seeds
Start with a healthy tomato from a healthy plant. Free of disease with characteristics you desire.
Cut around the circumference splitting the tomato into two halves.
Squeeze the seeds and pulp out, either directly into a jar or onto a plate.
Put all the pulp into a jar. I use Mason jars. Add clean tap water, about 1/2 again the amount of pulp you have. If you add too much water, the mold will not form as well.
Cover with plastic like a glad bag. Secure with a rubber band.
Poke a few holes in the plastic for air circulation.
Set on a window sill out of direct sunlight.
After a few days, mold should start to grow. Within about a week, your juice should look something like the picture below.
Pour the liquid into a sieve. Rinse them thoroughly.
Pour the seeds back into the jar. Fill the jar about half full with fresh clean water.
All of the viable seeds will fall to the bottom. The bad seeds will float to the top (as shown in the photo).
Scoop off the bad seeds and throw away. Dump the good ones back into the sieve for another rinse.
Spread the seeds out on a paper towel on a window out of direct sunlight to dry.
Leave for about a week. Then gather the seeds up, put them into an envelope, mark them and store in a cool dark place for planting next year.