How To Tell if Blueberries Are Bad

Justin Micheal

Food Writer & Editor in Chief For KitchenSanity

Justin Micheal is KitchenSanity's founder, food writer and editor in chief. As an expert home cook with over 30 years of daily cooking experience and food handler certifications, he's a pro at experimenting with recipes and a stickler for food safety. He writes informative and detailed guides about cooking basics such as proper food storage, cutting and cooking methods, and choosing the right products to make cooking easier.

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Do you have a container of blueberries in your fridge that are starting to look a little…not so fresh? They may still be good to eat or use in your favorite recipe, but how do you tell if blueberries are bad?

You can tell that blueberries are bad when they have become too mushy, the skins have split and are leaking juiced, have become dry and shriveled, or have mold growing on them. If you see any signs of mold or spoilage, it’s best to throw the entire package out.

I know buying blueberries is expensive, but sometimes it’s better to toss them when they go bad in the fridge. In this guide, I’ll share the best signs that your blueberries have gone bad.

How To Know If Blueberries Are Bad

They Are Mushy

Are Mushy Blueberries Safe To Eat? Mushy blueberries are generally safe to eat if there isn’t the presence of mold or splitting skins. The soft, squishy berries are probably just overripe and need to be used up quickly.

The texture of mushy blueberries can be grainy and unpleasant. So, it’s better to use them in smoothies, baked desserts, or jams.

The Skins Have Split

When the skin of your blueberries split, and it wasn’t from rough handling as you were cleaning your blueberries, it can indicate two problems and reasons why you should avoid consuming them.

Sometimes fresh blueberries will split if they become overhydrated. As moisture gets absorbed, the skins stretch like a balloon. At some point, the skin can no longer handle the pressure and splits open.

More often, like strawberries, the skin is starting to break down and can no longer hold the contents of the blueberries. This goes hand in hand with mushy blueberries.

The biggest problem with split blueberry skin is that it allows bacteria, pathogens, and pests to make a home inside the blueberry. This can lead to food poisoning when consumed.

And the juices that leak out onto other blueberries can also contaminate them. Before using, you should toss out any split blueberries and clean others very well.

If unsure, get rid of them and save yourself a potential trip to the emergency room.

They Are Dry And Shriveled

As decomposition happens, an old blueberry will dehydrate and become dry. As it dries, the skin will become wrinkled or shriveled.

Rehydrating blueberries doesn’t work the same as rehydrating vegetables. For example, they won’t firm up like when you give celery a cold water bath. They’ll just kind of float in the water.

So, consider these rotten and discard them.

They Taste Bitter

A bitter blueberry is the result of bacteria that has broken down the sugars in the berry, leaving it to taste bitter.

Sometimes you’ll find these amongst fresh blueberries. It could be the result of poor grading or just how nature intended it to have a short shelf life.

discolored blueberries

Either way, there is no way to save these bitter berries, so separate them from the rest and add them to your compost bin if you have one.

If your blueberries taste sour, you’ll enjoy my guide on why they taste sour and how to make them taste better.

They Are Discolored

Discolored blueberries can still be good but often taste bad. Discoloration can be seen in the form of red and white patches amongst the blue.

They will often have sour or bitter notes, and definitely not what you expect from a fresh blueberry.

Discolored blueberries are generally bad, but they don’t spread their issues to nearby berries. Don’t eat or cook with them. Instead, throw them out.

There Is Mold

Mold on blueberries is usually white, gray, or green. It will generally look fuzzy rather than powdery. You should throw out moldy berries right away.

rotten moldy blueberries

Some people may choose to inspect and clean other nearby berries, but I always toss the whole batch. Once you see mold, it’s often already too late to prevent it from growing on other berries.

But wait, there was white stuff on my fresh blueberries when I bought them! The good news is that the waxy white stuff on blueberries, also called bloom, is a natural protective barrier that’s perfectly safe to eat.

Bad Blueberry FAQs

If One Blueberry Is Moldy Are The Rest Bad?

Yes and no. Mold spreads via contact, so you may be able to save the rest if you take out the moldy berries and any others touching them and clean them well. Still, the best practice is to toss them all.

Can Bad Blueberries Make You Sick?

Yes, bad blueberries can make you sick. You may experience foodborne illness or a common blueberry pathogen called the human norovirus. See a doctor immediately if you experience any symptoms after eating bad blueberries.

What Happens If You Eat Moldy Blueberries?

Eating moldy blueberries can cause respiratory reactions, trigger allergies, or just make you feel sick, so it’s better not to take a chance.

Can Frozen Blueberries Go Bad?

Yes, frozen blueberries can go bad. After being frozen for too long, they will become freezer burnt, mushy when thawed, and may contain bacteria that can make you sick. Bacteria often will still grow in freezing conditions, just more slowly. Clean your blueberries before freezing them, and keep them frozen for up to 2 months.

Written By Justin Micheal

Justin Micheal is KitchenSanity's founder, food writer and editor in chief. As an expert home cook with over 30 years of daily cooking experience and food handler certifications, he's a pro at experimenting with recipes and a stickler for food safety. He writes informative and detailed guides about cooking basics such as proper food storage, cutting and cooking methods, and choosing the right products to make cooking easier.

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