Be careful: preserved zucchini and pumpkin seeds can give poisonous fruits!
Your zucchini that has grown far too big is fantastic for the soup.But before you think 'what lovely big seeds are in there. I'm going to save that for next year'. The fruits from crossed seeds can be poisonous.
Are you sure your zucchini didn't get crossed? Same goes for pumpkins. All from the same family. Bees fly from flower to flower and thus you get cross-pollination within the family.
Squashes and courgettes cross very easily. Even over a long distance (100 meter +).
The risk of cross-pollination is very high, which is why I would never store zucchini or pumpkin seeds myself. It is possible, but that is an accurate job that has to be done by hand. It listens closely, because you have to close the new flowers in time before a bee comes by!
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