I ate some blackberries (last June) and kept some seeds. I tried two ways to germinate some.
First way, I used an empty white plastic jar where I put some water and seeds. I put the jar in a dark place (in my closet).
Second way, I used an empty transparent plastic cookies box, where I put some seeds between some wet paper towels. I put the box in my fridge.
During the last two months I checked every two weeks to look for some difference. The only difference I was able to see was the decay of the seeds in the box in the fridge.
I really would like to understand how I can germinate these seeds, so later on I can expect to see them growing and making fruits!
I don't know if it's pertinent or not, so I added the picture of the rest of the seeds.