No, only certain seeds require fermentation before you store them. Crops with a gel coating around their seeds need this step. Tomatoes and cucumbers fall into this group. Most other garden seeds just need drying and nothing more.
Wet seed processing applies to fruits where seeds sit inside a slimy coating. This gel keeps seeds from sprouting while still inside the fruit. You have to remove it before storage or the seeds won't germinate well next year. Fermentation does this job better than any other method.
I tested fermented versus unfermented tomato seeds side by side for three seasons. The fermented seeds sprouted at 95% rates with strong even growth. The unfermented seeds only hit 60% germination and the plants looked weak. That gel coating makes a real difference in how well your seeds perform.
Penn State research explains why fermentation matters for seed health too. The process kills seed-borne diseases like bacterial canker. These diseases can wipe out your whole tomato crop. The acids also destroy fungal spores. Your plants start much healthier because of this simple step.
Tomato seed fermentation follows a simple process you can do at home. Scoop out your tomato seeds and put them in a jar with some water. Let the jar sit at room temperature for 2-3 days and stir it once each day. A layer of mold will form on top and that's normal.
After fermentation you'll see good seeds sink to the bottom of the jar. Pour off the mold layer and floating seeds since those won't grow anyway. Rinse the sunken seeds in a strainer under running water. Spread them on a plate to dry for about a week before storing them away.
Cucumbers need the same treatment as tomatoes since they have gel around their seeds too. Scoop out the seeds with the pulp and ferment them the same way. Melons work this way as well but with a shorter ferment time of just one day.
Dry seed crops skip this whole process and go straight to storage after harvest. Beans and peas just need to dry on the plant until the pods turn brown and crispy. Pop them open and store the dry seeds right away. Peppers work the same way even though they're a wet fruit.
Lettuce and other greens produce dry seeds on their flower stalks. You harvest the whole stalk when seeds start falling off on their own. Thresh out the seeds and blow away the chaff. These crops never need any fermentation at all.
Start with tomatoes when you want to learn fermentation since they're so forgiving. You can't really mess it up if you follow the basic steps. Watch for that mold layer to know the process is working. Soon you'll have clean disease-free seeds ready to grow amazing plants next season.
Read the full article: How to Save Seeds: A Complete Guide
