The potato fruit in the picture are unripe. What do you do with them? You throw them out unless you are into breeding new cultivars of potatoes. They will not produce a usable potato crop next year, just tiny tuberlets. And they will not produce the variety they came from. However, you could try breeding your own new varieties if that interests you.

Here is a link that might be useful: Breeding potatoes

I know they most likely won't produce the same variety. I'm interested in saving them for the winter and seeing what I can do. That's why I posted here.

Did you look at the link? It explains how and when to grow the seed on to get your own new varieties, if that's your intention.