Blueberries stay fresh up to two weeks if stored in the refrigerator, according to About.com. Best results are obtained when the berries are freshly picked and stored in a rigid container covered with plastic wrap.
About.com Home Cooking guide Peggy Filippone explains that blueberries deteriorate more quickly when exposed to water. It's best to choose berries that have not been misted in the supermarket, store them unwashed and rinse them just prior to use. Because blueberries are highly perishable, it's advisable to use them as soon as possible.
It's simple to freeze blueberries for future use, according to StillTasty. The blueberries should be rinsed in cold water, patted dry, spread out in a single layer on a cookie sheet and placed in the freezer. Once the blueberries are frozen, they can be transferred to airtight containers or freezer bags and stored in the freezer for up to a year.