You can store your blueberries in a number of ways. Before you store the berries, carefully go through the berries, discard any soft berries or berries with white areas on their skin, and remove stems. If you are planning to refrigerate or freeze your blueberries, do not wash the berries before you store them; wait to wash the berries until you are ready to use them. Cool your berries down to room temperature before storing them. By doing this, you can avoid a lot of condensation in the blueberry containers. Spread the blueberries out on cookie sheets or jelly roll pans and place the sheets or pans in front of a fan for a while before storing them, your blueberries will last longer. If you refrigerate your blueberries, put a folded paper towel in the container to absorb some of the condensation. Stored this way in the refrigerator, your blueberries should last at least a week. I have found that the best way to freeze blueberries is to freeze them individually. After I have graded the berries I leave the blueberries in a single layer on cookie sheets and place the cookie sheets in the freezer until the berries have frozen. (If your household is like mine, you may want to let family members know the cookie sheets are in the freezer, so someone does not tip the pans by accident. Believe me, chasing blueberries across the floor loses its appeal pretty fast.) When the berries are frozen (within 24 hours), I transfer the berries to freezer bags or other freezer containers. When you are ready to use the berries, you will find them easy to measure. The berries should be good up to twelve months.
As soon as you get your hands on some blueberries, rifle through them a bit and make sure there aren't a few moldy berries hidden inside. If you spot one that's gone fuzzy or looks shriveled (which means it's on the brink of going bad), remove it immediately. Mold can spread quickly between the berries when they're in such close contact—so even if you know how to store blueberries properly, a little hidden mold can sabotage the whole pint.
The absolute best way to keep berries fresh is to avoid rinsing them until you're ready to eat them. That being said, it isn't always convenient to rinse and dry a handful of blueberries every time you're feeling peckish. So you can rinse them in advance, under cool water in a colander, so long as you follow the next few steps to ensure they get dried off before storage.
If you've rinsed your berries, lay them out to dry on a paper towel-lined tray, rolling them around a bit until there's no visible water left on them. Then transfer the berries to a breathable container that you've lined with paper towels, such as the box or basket the berries came in. The paper towel will absorb any excess moisture, and the air circulation will deter mold.
Pop your container of blueberries in the fridge—but don't keep them in the crisper drawer, where air doesn't circulate too well. Depending on how ripe they were when you bought them, the blueberries will stay good for up to a week when stored this way.
As we stated above, spread your blueberries out on a rimmed baking sheet, let them firm up in the freezer for a couple hours, then transfer them into a resealable plastic bag and pop them back in the freezer. They'll keep for at least a few months, which means you can make blueberry pie...for Thanksgiving.