Here are some tips from North American Blueberry Council:
- Choose fresh blueberries that are firm, dry, plump and free of leaves and stems. The skin should be smooth and deep purple-blue, with a silvery-white bloom - a natural, protective, waxy coating.
- Avoid containers that have juice stains, which may mean the berries are crushed and possibly moldy; soft, watery fruit that indicates the berries are overripe; and dehydrated, wrinkled fruit that means they have been stored too long.
- Store fresh blueberries covered in the refrigerator, and use within 10 days of purchase. Wash berries just before serving.
- To freeze, use berries that are unwashed and dry. Cover the container with plastic wrap or a resealable plastic bag, or transfer berries to a plastic bag and seal. Another method is to arrange dry berries in a single layer on a cookie sheet and freeze them. When frozen, transfer the berries to plastic bags or freezer containers. Wash the berries just before using.