Will Blueberries Ripen if Picked Early?
Blueberries (Vaccinium) are high in antioxidants and are versatile in recipes. Although some blueberry plant varieties are hardy in U.S. Department of Agriculture plant hardiness zones 3 to 7, other varieties are hardy in warmer zones. For example, "Misty" (Vaccinium x "Misty'"), a Southern highbush variety, is hardy in zones 5 through 10.
From muffins to milkshakes, blueberries can be a well-used fruit from your garden. Ideally, blueberries should be ripe before they are picked. Otherwise, they have a hard, sour flavor. If blueberries are picked early, you still may be able to ripen them.
When to Harvest
Blueberries are ready for harvest between late July and the middle of August. They should be blue or blue-purple before harvest and larger berries are sweeter. Even when blueberries are blue, The Old Farmer’s Almanac's website recommends waiting a couple days to pick them for the best results. Ripe berries should easliy fall off the bush when picked.
If blueberries are slightly purple or red, you can still harvest and ripen them, but blueberries picked while they are white and green will not ripen. Ripening picked berries does not make the blueberries sweeter.
How to Ripen
If you picked your blueberries a bit too early and they’re slightly blue, red or purple, you may be able to ripen them. Keep them at room temperature, and place them in a paper bag. Using a plastic bag will cause the blueberries to rot from oxygen deprivation. A paper bag increases the ripening process by trapping the ethylene gas released from the blueberries. Store the bag in a dark, cool place.
This method only ripens blueberries to be juicier; it doesn't make them sweeter or more flavorful. Blueberries picked when ripe have more flavor.
How to Handle After Picking
Ripe blueberries should never be placed in a paper bag, container or sunlight. Instead, place them in an open container. Blueberries can be delicate, so use a shallow container rather than stacking blueberries too high which can damage the berries at the bottom. Remove berries that are damaged, moldy or diseased.
Ripened blueberries can be kept in a refrigerator for 10 to 14 days. Wash the berries only when you’re ready to use them so that they remain fresh. Putting wet blueberries in the refrigerater can casue them to mold, notes the University of Minnesota Extension. Don’t place unripened blueberries in a refrigerator or freezer.
How to Freeze Ripe Blueberries
If you need to keep your blueberries longer than 10 to 14 days, freeze them. Freezing unwashed blueberries may help their skins soft, notes PennState Extension. If you do wash the berries, be sure that they are completely dry before freezing.
Line blueberries on a cookie sheet, and put the cookie sheet in a freezer until the berries are frozen. Then pour them into a container or plastic bag for storage in the freezer until you are ready to use them. Rinse the berries in cold water before using them. Be sure to use frozen berries within one year, for best quality. Over time, the berries will start to develop freezer burn and the texture of the berries may start to change.