The first and most important step is to choose a zucchini squash from a plant that is healthy and green, and has always produced flavourful, good quality fruit. You reap what you sow, so make sure the fruit you choose for collecting comes from a plant with a good history. Once you pick a fruit, make sure you cut it open and have a little sample – do not choose fruits that come from diseased plants, are from the very end of the harvesting season, or taste bitter.
Next, use a sharp knife to slice the zucchini in half. Place the halves on a flat counter, with the cut side up, and use a spoon to scrape out the seeds from the centre of the fruit. At this point, the seeds will be trapped in the pulp of the fruit, so give them a good wash, to separate the seeds from the pulp. However, while it is essential to wash them, make sure you do not soak the seeds.
Then, spread the wet seeds out onto a flat, clean tray, and look through them carefully, inspecting them. Remove and discard any seeds that are crushed, flat, or do not appear to be in very good condition. These will not bear any fruit.
Now that you have washed the seeds, and removed any bad ones, proceed to spread them all out on a paper towel, and let them air dry naturally. As they dry, keep the seeds away from any moisture, or from excessive heat – for example, do not keep them near your kitchen sink, or put them out to dry in the sun.
After the seeds have dried completely, you can store them in paper bags, or even in envelopes. Make sure you select a storing space that is cool and dry – this will increase the longevity of the seeds, and they will keep for a couple of years, as long as you make sure they are not exposed to any sort of moisture or extreme heat.