Scoop the seeds into a clean bowl or jar. If the seeds are not floating in liquid from the tomato, add up to a cup of water to help separate the seeds from the pulp. Then set the bowl of tomato seeds and pulp in a warm, out of the way spot. You will need to allow 2-4 days for the fermentation to take place. As it does so, the mixture is going to begin to smell awful, so store the bowl where you won't pass by frequently. What you eventually want to see is a layer of mold on top of your seeds & pulp. The process is done when bubbles start rising from the mixture or when the entire bowl is covered with mold. Don't leave the seeds fermenting past this stage or they may begin to germinate.
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