Delicious Strawberries Eight medium-sized strawberries contain a whopping 140 percent of the recommended daily amount of vitamin C. In addition, strawberries are a good source of folic acid, potassium, and fiber. The sweet, juicy berries are fat-free and low in calories. Freeze extra unsweetened strawberries for later use. Place berries, in a single layer, on trays in the freezer. Once frozen, place the berries into freezer bags or other sealed containers for storage in freezer. The frozen berries will keep for many months. Whether you pick your own or purchase strawberries from the supermarket, remember that storing strawberries more than five inches deep will bruise the lower berries. Unripe berries will not ripen once picked so pick berries that are fully ripe. To prevent spoiling do not wash the berries until ready to use them.