Remove any soft or crushed berries from picking container. Use these berries immediately. Remove any stems or leaves from the remaining blackberries.
Place the sorted berries into a storage container. Stack the blackberries no more than two berries deep, or the weight of the berries on top crushes those on the bottom.
Leave the container uncovered so moisture isn't trapped inside. Store the berries in the refrigerator for up to five days.
Line a tray with wax or parchment paper. Place the sorted berries on the tray in a single layer.
Place the tray of blackberries in the freezer. Freeze for two to four hours, or until the berries are frozen throughout.
Transfer the frozen berries to a freezer-safe storage container or bag. Seal the container closed and store the blackberries in the freezer for three to six months.