First, I don't grow these, but U of Idaho suggests:

= " best sown as soon as it is ripe in a cold frame. Stored seed requires 2 months cold stratification. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts.

Germination of freshly harvested seeds occurs 3-6 weeks after seeding and is generally good (50-90%), Stratification is not required if fresh. Seed viability remains good for about 1 year after harvest, but declines rapidly in succeeding years."

If you do chose to store for a few months and not sow immediately, cool and dry for storage. If you are in a humid warm climate, that site may be sealed in a container in your refrigerator after drying....just an envelope on my desk works for seeds for me, my house is on the dry side.

Any seedlings yet? I wish my haskap had some berries. I want to seed a little on the woods edge and in clearings on my property. It would be a nice addition to all the wild raspberries.

How did you collect the seeds? Blender? Any extras you might sell/trade?

I threw a few seeds into a pot.. just lightly covered them on the top of the soil. I never stratified them, but after a few weeks I have one so far that is growing. When I can get more berries I will stratify to get better germination. The seeds were not hard to extract. If you were going to try for a lot, then I would say the blender is going to be your best bet.