Moldy berries are a common annoyance for anyone who throws fresh berries in the fridge without thinking twice. Follow this simple guide to learn how to keep blueberries as fresh as possible.
Why Do Berries Go Bad So Quickly?
When exposed to the many natural conditions in your kitchen and refrigerator, blueberries, raspberries, and blackberries spoil quickly. Moisture is the primary cause of fresh blueberries going bad quickly, often within two days if not refrigerated. Light and humidity are two other factors that degrade the freshness of the berries, causing them to rot and develop natural contaminants that can cause foodborne illnesses. Berries should not be eaten if they develop moldy, white, or green fuzzy patches.
Berries purchased at the grocery store frequently have a "use by" or "best before" date printed on the packaging, indicating when they will go bad. However, many blueberry containers do not include this information. The best way to keep mold and rot at bay on your blueberries is to store them properly.
How to Store your Blueberries
Here's a quick rundown of the tried-and-true vinegar bath method for preserving blueberries:
1. Examine: Open your blueberry container and pour the contents into a colander. Remove any berries that are overly moist or have soft patches.
2. Vinegar bath: Combine one cup of white vinegar or apple cider vinegar and three cups of water in a large mixing bowl. Add the blueberries to the bowl, swish them around, and soak for 5 to 10 minutes. Most of the bacteria will be killed by the vinegar.
3. Rinse: Rinse the berries in a colander or strainer under cold water to remove the vinegar solution.
4. Dry: It is critical to thoroughly dry your berries in order to extend their shelf life. Spread your berries across a paper towel, then cover with another paper towel. Gently pat and rub the berries down with one hand to absorb all of the moisture. To dry the berries, line a salad spinner with paper towels and spin them.
5. Store: Refrigerate the fruit in a large, unsealed (or breathable) container. An airtight container can trap moisture, hastening the rotting of the berries. Place the fruit-filled container on the middle shelf of your refrigerator because the crisper drawer or top shelf will trap excess moisture and humidity.
How to Make Fresh Blueberries Last Longer
The key to keeping blueberries fresh for longer is to remove as much bacteria and moisture as possible, whether you grow them at home or buy them at the farmers' market. Here are some general guidelines to help your blueberries last longer:
1. Perform a pre-purchase inspection. Before purchasing blueberries from the grocery store, inspect them. If you have one overly moist berry in your batch, the rest are likely to turn quickly as well. When you get home, if you notice any blueberries that have mold, are leaking juices, or have soft patches, remove them from the batch before storing it. You can also remove the blueberry stems to extend the life of your berries.
2. Only wash before use. Wash your blueberries only when you're ready to eat them. Washing adds moisture to the berries, which accelerates the ripening process and causes them to spoil faster.
3. Store correctly. Your blueberries will most likely be crammed into the small container that stores sell them in. Taking your berries out of this container will help them last longer. Line a container with paper towels and arrange the berries in a single layer, leaving the top of the container open to allow the berries to breathe. Blueberries should be stored in a low-humidity, low-moisture area of your refrigerator, such as the middle rack.
4. Freeze in an airtight container. Frozen blueberries can be kept for six to twelve months, while refrigerated blueberries can only be kept for five days. Blueberries should be flash frozen to prevent them from clumping into an unusable ball. Place the berries in a single layer on a parchment paper-lined rimmed baking sheet, making sure they aren't touching, and freeze for two hours. Place the berries in a freezer bag or an airtight container after removing the baking sheet from the freezer. Thaw the frozen berries in the refrigerator for a day before using them, or add frozen blueberries to any of your favorite smoothies.