Great tips and advice on choosing and storing blueberries for maximum freshness and taste from the Paula Deen website:
When you are at the market or blueberry farm, choose the blueberries that are firm and have a uniform color with a white bloom. This next step for testing freshness is really important. Shake the container that the berries are in. Fresh berries will move freely. If they don’t, it’s usually an indication that they are soft and could be moldy. Use the same test when purchasing frozen berries. Shake the bag. If the berries move freely this is a sign that they have not thawed and been refrozen.
Remove any damaged berries before storing because those will spread mold. Store your ripe blueberries in a covered container and place it in the refrigerator. They will hold for just under a week. Don’t wash your blueberries until right before you are ready to eat them. Washing will remove the bloom and that is what protects the berries skin. Ripe berries can be frozen easily. Wash them first and remove any damaged berries. Allow to drain and spread them out on a wax paper lined baking sheet. Place in the freezer until berries are frozen then remove and put into individual zip lock bags. I like to freeze my berries in one cup measurements, which makes preparation more expeditious when I am ready to use them in a recipe.
Preparing Blueberries for use:
Fresh Blueberries are fragile. Wash them gently and gingerly pat dry JUST before use. If you are using frozen blueberries for anything other than cooking, thaw and allow them to drain before use. When using frozen blueberries for cooking, use unthawed berries for the biggest flavor punch. You will need to extend the cooking time when using frozen berries to accommodate for the excess moisture released.