Tomatoes are one of our most important crops that we grow! I’m sure you can agree, as they are used for so many different foods including:
- Tomato Pasta Sauce (paste tomatoes)
- Marinara and Pizza Sauce (paste tomatoes)
- Salsa (slicing tomatoes)
- Ketchup (slicing or cherry/grape tomatoes)
- Salads (cherry tomatoes)
- Sandwiches & Burgers (slicing tomatoes)
- …. We’ll stop here, because tomatoes can be used in nearly anything, you get the idea!
With that being said, it’s naturally very important to learn how to save heirloom tomato seeds and the process of fermenting tomato seeds. While you could be growing tomatoes from tomato slices, I don’t recommend this as a seed saving method for those who are trying to maximize their seed yields and germination rates for next year.
Fermenting Tomato Seeds
Fermenting tomato seeds is important for seed viability and health. During the fermentation process, the seeds of the Solanum lycopersicum plant are removed from the fruit, placed in water, and are allowed to ferment for a fewof days. This process removes the flesh and remaining sugars from the seeds, which would result in moldy seeds in storage. It also helps to remove many pathogens that might be lingering, which could cause pest, fungal, bacterial, or viral infection of the seedlings (you still want to only collect seeds from healthy plants, as there is still a risk of infection; fermenting seeds simply reduces the risk). As the yeast and bacteria grow and ferment the plant material over the 3 to 7 day time period, bubbles will begin to develop; slowly, the water will become quite scummy and the container will develop a very foul odor. This is a good sign, meaning that those microbial work horses are powering their way through the remnants of fruit, leaving behind clean seeds that will be able to be saved for a long period of time.
Before you can begin fermenting tomato seeds though, you’re going to have to harvest the seeds in the first place; and before you harvest, you should decide which types of tomatoes you would like to save.
What Type of Tomato Should I Grow?
There are three major types of tomatoes that are grown, with each serving a particular purpose. The first group we’ll discuss is very important on the homestead, as it is largely canned or frozen. You want to save seeds based upon your needs on your homestead- if you’re never going to eat tomatoes in your salads or make ketchup, then you may choose against saving cherry tomato seeds, for example. Before you head out into the garden to grab some tomatoes for seed preservation, keep these 3 main groups of varieties in mind, and choose wisely. After all, if you aren’t careful, you’re going to have more tomatoes than monstrous zucchini to figure out what to do with! Oh, and one last thing: saving heirloom tomato seeds is the best way to go, so avoid saving hybrids if possible. They don’t always grow true to type.
- Sauce and Paste Tomato Varieties: These tomatoes are incredibly important. With fewer seeds and more “meat”, these tomatoes are prized for making sauces and pastes. Many of these types of tomatoes grow on determinate plants, which is important for preservation. Determinate tomato plants stop growing when they reach a certain height, and are also known as bush tomatoes. Most of the fruit will ripen in unison, allowing you to preserve your tomatoes all at once! If you want to stockpile pasta sauce, tomato paste, or diced tomatoes in your pantry, this is a great tomato for you. Some varieties include:
- San Marzano
- Roma
- Amish Paste
- Slicing Tomatoes: Slicing tomatoes are largely indeterminate, producing long, trailing vines that will continue to flower and fruit as long as they can- until frost. These tomatoes are usually larger in size with more seeds; they are packed with flavor and ideal for sandwiches. They can be preserved as well; no tomato goes unwanted, here!
- Cherokee Purple
- Brandywine
- Oxheart
- Mortgage Lifter
- Salad Tomatoes: These little guys are incredibly prolific in the garden, so you probably won’t need too many, unless you are eating several with your salads! They are also great for producing ketchup or tomato mozzarella salad, which you might decide to do if they begin to pile up on your counters. Cherry and grape tomatoes have a few differences, so be sure to take this into consideration.
- Yellow Pear
- Black Cherry
- Gardener’s Delight
- Tiny Tim (window gardening/container gardening friendly!)
How to Harvest Tomato Seeds: Saving Heirloom Tomatoes
Once you have chosen your ideal tomato type, it’s time to learn how to harvest tomato seeds! You should only choose the ripest fruits for seed saving, in order to ensure maturity and the best germination rate. The tomato should practically fall off the vine- you could even use any tomatoes that have already fallen. If you are saving different varieties, please process them all separately; if you try to do them all at once, you run the risk of mixing up the names of the seeds; trust me, you don’t want this to happen. Saving heirloom tomatoes one at a time will prevent you from planting the wrong varieties in the wrong places.
- First, wash each tomato very well to remove any potential infectious material that may have splashed onto them by the rain, such as fungal spores or the eggs of pests. If you are harvesting paste tomato seeds, please note that you will not find as many seeds within them as slicing tomatoes so you might require several.
- Next, slice the tomatoes and remove the seedy pulp, avoiding the meaty walls. Place these seedy pulps into small jars, and cover them in warm water.
- If you are trying to save seeds from cherry tomatoes, you may choose to put the tomatoes into a blender with a plastic blade to save bulk seed. Strain the seeds from the juice, and place them in water. Never use a metal blade, as this will destroy the seeds rather than liquefy the flesh.
Moving Along to Fermentation: How to Ferment Heirloom Tomato Seeds
Now that you have your seeds ready to go, the rest is easy! I promise!
Make sure that all seeds and pulp are covered with water (they will float, and this is okay.) Allow the seeds to sit in the water for 3 to 7 days for the fermentation process to complete. The container will develop a scummy, molded surface; this is what you’re after! As this process continues, seeds will sink and the container will begin to stink. You’re going to be absolutely disgusted, but you’re going to need to accept a stinky kitchen for a few days. Don’t start this process a few days before hosting a party- you’ll regret that decision. As you near the end, you’ll notice that the seeds look much cleaner. The cooler the area is that they’re kept in, the longer this will take. Warmer temperatures are far more effective for fermentation.
Upon rinsing, the seeds should no longer have a slimy feel to them. Be sure that all flesh is removed from the seeds, or you risk a mold issue. Fine mesh strainers are excellent for seed saving purposes, and most dollar stores (such as our Dollar Tree) carry these handy little kitchen utensils.
It’s time to dry them!
Drying Heirloom Tomato Seeds
Once fermentation is complete, lay out some paper towels and label them with the tomato variety. Smear the wet seeds across the paper towels, being sure to wipe away any leftover pulp if it is noticed. Don’t allow the seeds to clump up. If this is an issue, simply redistribute the seeds with your finger tips in 12 to 24 hours to break up clumps. The seeds should be allowed to air dry for up to a week, at which time you can store them in bags, label them, and put them away until spring planting comes around!
