Did you know that frozen blueberries will keep for a year? Soak for 2 minutes (or longer) in a bowl of water with 1 tablespoon of vinegar. Rinse, dry and spread them in a single layer across a baking sheet. Freeze them. Finally, transfer the blueberries to a freezer-safe resealable bag and put back into the freezer to store. If storing in the fridge, wash the same way. This will ensure their freshness for up to 10 days. Eat them raw, bake into a pie or plop in an icy drink.