From Health magazine
Q: What’s the best way to freeze extra summer berries?
A: The trick: Make sure they’re dry. After you’ve rinsed them and removed the stems and hulls, shake berries on a paper towel–lined, rimmed baking sheet until they’re completely dry.
Next, spread in a single layer on a dry, rimmed baking sheet and freeze for about an hour. Remove from the freezer, transfer into plastic bags, removing any excess air, and store in the freezer up to 6 months.