If you have fully ripened tomatoes that you wish to make seed with but not sure how then follow the directions below. Making seed from tomato is alot more easier than you think but once you try, you be amazed how simple it is.
Biggest issue people have with tomato seed they removed from the fruit is that the seed will not germinate easy. The reason is that the seed inside the fruit has a gel coating (why seed do not start growing while inside the tomato). We remove this gel coating inhibitor through fermentation (STEP 2). Wash any dirt away on the tomato then squeeze out the pulp in a jar (or container) that has a lid. After the jar is filled (no more than half to save room for another step later) with the pulp, seed and juice then cover with a lid.
Place the jar (or container) into a warm and dark location and wait about three days. During this time twice a day give the jar a shake. The Tomato juice will do the rest.
After days have past top the jar up with water and cover again. Shake several times then let it set a few hours. Thanks to the water the pulp should rise to the top. Seed that are at the bottom is the seed you want. Remove lid, scoop the top material out. Pour the contents of the jar into a strainer. Then dump seed onto a plate (can also place wax paper on plate first). After a few days of drying the seed will be ready to use or store (Tomato seed can last up to three years if stored well).