Start by washing the blackberries. Keep in mind this is a very delicate fruit so you don’t want to scrub too hard. Instead, wash them very gently with cold water to make sure they are not damaged in the process. As you wash your berries, take the time to remove any dry or rotten berries. You don’t want them to get mixed with your frozen blackberries!

Once the berries are cleaned thoroughly, use a paper towel to dry them. Leave them under a fan or in an open space so that they dry up properly. Line a baking tray with parchment paper and spread the blackberries on it. Don’t forget to use the parchment paper. Otherwise, the berries will stick to the base of the tray as they freeze.

Place the tray in the freezer. Make sure to place the tray on a leveled surface otherwise your berries will roll onto one side. The berries will freeze in a few hours. However, it is best to leave your blackberries in the freezer overnight.

Once the berries are frozen solid, it’s time to transfer them from the tray to a heavy-duty freezer bag. Squeeze out as much air from the bag as possible. It is advisable to use a vacuum-sealing device to seal the bags. However, if it’s not available, you can use a straw to suck out air from the bags. Place the bag in the freezer.