It's harvest time! And if you've had a good crop of tomatoes this year, like I did from a plant someone gave me last spring, you're gonna want to save those seeds.
By taking a couple days to ferment the seeds - in the juice - you will have cleaner, more viable seeds. In the video I put my seeds "in the windowsill" but that was a shady spot. You want to keep them out of the sun during the process.
If you use a paper towel to let them dry, just make sure you shake them around or they could stick to the paper. I transferred mine to a white tea towel, or you could use a coffee filter. They should be dry enough to store in a day or two.
Give it a try! And if you have seeds you want to swap with me, let me know.