This year I decided to save some seeds from my dad’s heirloom tomatoes. There are a few small varieties I love, and I want to grow them next year… Plus, this way I can share seeds with others.
It’s super easy, though it takes more effort than most people realize. Tomato seeds are best once they’ve been fermented, though the process isn’t absolutely vital. This process helps weed out the bad seeds and makes the seeds less likely to carry diseases. It also helps separate the seeds from the clumpy tomato gel.
I happened to be making some sundried tomatoes, so when I scooped them out for better drying I just put all the seeds from one variety of tomato in a glass.
Next, I added about an ounce of water, and covered the glass tightly with Saran Wrap. I poked a slit into the plastic wrap with a knife so air can aid in the fermentation process. I set the glass on my kitchen window sill where it’s out of the way, and left it there for about a week. It’s recommended that you leave it for 3-5 days.
The seeds will develop a disgusting moldy film on the top— that’s okay, it’s supposed to happen! It might also stink. Mine sure did.
As the fermentation happens you’ll notice that the seeds mostly sink to the bottom, though a few will float to the top. This is also a good thing. The good, healthy seeds will sink, and the bad ones will float.
After a few days, I lifted the plastic wrap off and gently lifted the moldy film off with a fork. Then I also slowly and gently poured off some of the water and the floating seeds (though some of the floating seeds stuck to the mold). Next, I poured the rest of the glass out through a fine strainer and rinsed the seeds with cool water very thoroughly.
Next I gently blotted the seeds with a paper towel, then poured them into a plate to dry. Do not leave the seeds on a paper towel or paper plate to dry as they’ll stick. Every few hours I tapped the sides of the plate to get the seeds to separate from each other.
Once they’re completely dry they’re ready to store. I plan to put mine in a small glass jar, although a paper envelope would also work.