How to Collect & Save Tomato Seeds

If you’re a tomato lover it’s time to start thinking about collecting and saving seeds for next season’s crop. There’s a fancy way to do it, a human jump-started fermentation process, and then there’s Emily’s way, let nature do the work for you, simple and easy.

You probably came across the “fancy way”, the fermentation method, when surfing the web. Harvest the tomato of your liking, scoop or squeeze out the seeds, which will come along with juice and inner flesh or gel, and run it through a fermentation process. It takes about 2 weeks. It’s actually not terribly difficult and it allows you to collect seeds from the exact fruit you’d like to replicate. It’s perfect for heirloom varieties, especially if you plan to share your seeds with friends.

But if you’d like to skip the first step and you’re happy to leave a few tomatoes on the vine for seed saving then you’re nearly there. Fruit will naturally ferment as it over ripens and tomatoes are no exception. Simply leave a handful of tomatoes on the vine to ripen past their prime.

Fermentation Process:

• Cut your tomato in half and scoop or squeeze out the seeds into a cup.
• Add 1/4 cup to 1/2 cup water.
• Set the cup in a shady location for 3 to 5 days. A thin moldy layer may form on the surface, that’s okay.
• After 3 to 5 days remove the layer of surface mold.
• Add more water and stir. The good seeds will sink to the bottom.
• Skim or carefully pour off the floating bits of pulp and seeds.
• Repeat until the water is clear and you’re left only with seeds at the bottom of the cup.
• Pour or drain out your seeds onto a paper plate in a single layer and leave them to dry, again in a shady location.
• Label your paper plate if you’re working with more than one variety.
• Store seeds in an airtight container in a cool, dark corner of your house or fridge until you’re ready to plant in the spring.

Replicating Nature:

• Collect the fruit when it’s puckered and shriveled looking (from the vine or on the ground beneath your plants). You’ll notice they have a pungent aroma, that’s natural fermentation.
• Break and spread the tomato(s) open on a paper plate or paper towel so the seeds are exposed in a single layer.
• Leave the seeds to dry in a shady location.
• Store seeds once dry. I put paper towel and all into my storage container.

It’s best to save seeds from open-pollinated, heirloom varieties. Seeds from hybrids, like sweet 100’s and Early Girls (two of my favorites), can be saved but there’s no guarantee the fruit will be of the same quality the following season. However, I love and admire the vigor of volunteers and will often make room for these plants, hybrids included, when they pop-up in the garden. Why not? They usually taste amazing.