Some examples of dry seed: Beans, peas, lettuce, herbs, ornamental flowers.
Harvest the seeds when the pods are fully mature. The seeds should be dry and brown.
Store them in a dry area before separating them. If the pods crumble in your hand, they are dry enough to process.
Crumble pods or seed heads into a bowl.
Shake the bowl so the seeds fall to the bottom and the chaff (leaves, stems bits, flower parts) sits on top.
Separate the seeds from the chaff with a screen.
Cleaning wet seeds with no pulp
Wet seeds with no pulp are fruits and vegetables like peppers, melons, and pumpkins.
Harvest the fruit when it is fully ripe on the plant.
Long-keeping fruit (squash, pumpkins) should age another three weeks or so to allow the seeds to mature further. Short-keeping melons and peppers do not need this additional maturing period.
Cut the fruit open (across the ‘equator’) and scoop out the seeds. (Eat the rest!)
Rinse the seeds and put them on a plate or sheet of glass to dry. Avoid most papers, as seed sticks to it. Brown (kraft) paper works fine, but you will have to stir the seeds daily.
Stir the seeds from time to time to ensure they are all exposed to the air, and all dry out.
Seeds that are lumpy, mouldy, or discoloured should be tossed out (or used in soup).
Cleaning wet seeds surrounded by pulp
Seeds that are surrounded by a jelly-like pulp, like tomatoes and cucumbers, fall into this category.
Harvest the fruit when it’s fully ripe on the plant.
A cucumber should be large and yellowed. Tomatoes should be vine-ripened. Green tomatoes harvested at the end of the season will turn red, but these are not ‘ripe’ for seeds. Do not use these. Use tomatoes that ripened on the vines.
Cut fruit in half and squeeze or spoon the seeds into a jar. Cover the jar with cheesecloth, or put a loose lid on it.
Let the jar sit at room temperature for 3-4 days. It’s okay if mould grows on it, and the concoction gets smelly. Cheesecloth will help keep fruit flies out.
When the pulp is fully rotten, pour water into the jar. Stir. Let settle. The good, heavy, seeds will sink and the pulp and mould will rise. Carefully pour off the pulp only. Repeat until the seeds and the rinse water are clean (2-3 times, perhaps).
Strain the clear water and seeds through a sieve. Flip the seeds onto a plate or piece of glass, spread them out, and let them dry. Stir them around every day or so, so they don’t get stuck to the plate, or clump up.