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Saving Tomato Seed - Fermenting

How to Save Tomato Seed - The Fermentation Method

Saving your own tomato seed is an easy thing to do and will save you the cost of buying expensive seed the following year. There are a couple of methods that you can try.  In this article we will go through how to ferment tomato seed in water to remove the gelatinous coat that can inhibit germination. Fermented seed tends to be viable for longer than non fermented seeds so you should be able to store the tomato seeds for about 3 years if needed. You cannot save F1 tomato seeds and get the same tomato next year, it will be some variation on one of its parents so will be a complete surprise on how it will turn out! (If you want to air dry your tomato seeds instead check out our article here). 
Ripe Tomatoes
Step 1
Choose a number of ripe tomatoes that you want to save your seed from. To ensure the seed is fully mature pick tomatoes that have gone squishy and ones you probably wouldn't want to eat.
Tomatoes Cut in Half Showing the Seeds
Step 2
Cut the tomatoes in half to expose the seeds.

Clean Glass Jam Jar
Step 3

Find a clean jam jar.
Water in the bottom of a jam jar
Step 4
Put a couple of centimetres (1 inch) of water into the jam jar.
Tomato Seeds Fermenting in the Water in the Bottom of  a Jam Jar
Step 5
Either squeeze or scoop the seeds with a teaspoon from your tomatoes into the water in the jar.
Tomato Seeds Fermenting in Water at the Bottom of the Jam Jar
Step 6
The tomato seeds will sink to the bottom of the jar.
Fermenting Tomato Seeds in a Jar covered with a Kitchen Towel Lid
Step 7
Do not put an airtight lid on the jar. As the seeds start to ferment they will produce a gas which may cause the jar to explode if the gas can't escape!

Instead cover with a piece of kitchen towel secured with an elastic band. This will allow the gas to escape whilst keeping the fermentation smell in and keeping flies out.

If you are saving more than one variety of tomato seed attach a label with the variety name onto the jar. One tomato seed looks very much like another and you might not remember which is which otherwise.
Fermenting Tomato Seeds in a Jar covered with a Kitchen Towel Lid
Step 8
A mould will form on the surface of the water. The seeds should be left in the water for 5 days or so. Then remove the mould and any tomato seeds that have floated. Then pour the rest of the water in the jar through a sieve to catch the remaining seeds and rinse the seeds in fresh water.
Fermented Tomato Seeds Drying on a Terracotta Saucer
Step 9
Next spread the seeds out to dry before storing. You can use a paper towel for this but the seeds may stick. We dry our seeds on an unglazed terracotta saucer placed in a warm room, as the terracotta absorbs any moisture. The seeds do not stick to this. 

Once the seeds are totally dry place them in a paper envelope, labelled with the name of the seed and the date collected.

For advice on storing seed check out our helpful guide here
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