One of the advantages to growing heirloom tomatoes, as opposed to hybrids, is that you may save the seeds and count on them producing true in the next generation. There are a few steps to saving tomato seeds, but it is an easy process. Tomato seeds are encased in a gel which contains growth inhibitors to prevent the seed from sprouting inside the tomato. This gel needs to be removed through a fermentation process in order to save the seed. Choose a quality tomato that is fully ripe. Cut it in half so that the stem end is on one side and the blossom end on the other. You will easily see the seed cavities when you cut the tomato this way. Using a spoon, scoop the seeds into a glass container. Add a small amount of water so that the seeds are floating in liquid. Cover the top of the container with cheesecloth or a coffee filter and secure with a rubber band, to keep insects away. Allow this to sit for 2 – 4 days so that the mixture can ferment. Don’t forget to label each variety carefully to avoid confusion later on. A layer of mold will form on the top of the liquid. When the layer is fully formed across the top, and the seeds have settled to the bottom, the process is complete. Skim the mold from the top. Strain the seeds and rinse well under running water until all the pulp is removed and only seeds remain. Spread the seeds onto a plate or a coffee filter and allow them to dry thoroughly. They tend to stick to paper towels, so it is best not to use them. The seeds will take several days to dry. Spread them around occasionally to prevent them from sticking to each other. Once they are completely dry, store them in an envelope that is marked with the date and variety. It is best to store your envelopes in an airtight container such as a jar or a plastic bag. This simple process is an easy way to save money, and to share or trade seeds with friends.