Our favorite summer fruits—berries chief among them—are no longer at their sweet, jammy, (relatively) affordable peak. That doesn’t mean that you can’t still get decent berries, of course. It does, however, mean that you should prepare to pay handsomely for those precious pints.
With all of this in mind, how do you make the most of that $6 pint of imported blueberries—and is it acceptable to call in the National Guard if some of them are already moldy when you get them home? We asked Dr. Seanna Annis, professor of mycology and extension professor at University of Maine, as well as a blueberry pathologist—for the dirt on moldy bluebs.
Do you have to throw away all the blueberries?
Short answer: no. Unlike soft or porous foods like bread and soft cheese, you don’t have to toss an entire carton of berries just because one of them is infected with mold.
Now, if most or all of the berries are moldy or showing signs of rot, it’s time to toss them in the compost.
What to do if you find moldy blueberries
First—and this may sound a bit obvious—“I would throw away the moldy berry,” says Dr. Annis. Then, “What you can do is spread out your berries on a paper towel, and go through and see if there are any other moldy ones.”
This isn’t just about disposing of the bad berries: It’s also a matter of salvaging the uninfected ones before the fungus can spread. This mainly happens when the berries have been sitting there for a while, says Dr. Annis.
While it’s technically possible for some of the other berries in the pint to be infected without showing any visible mold or rot, Dr. Annis says, the types of fungi found in blueberries are unlikely to cause human illness. “If they’re firm and they don’t seem to be contaminated, then they are probably okay to eat.”
How to keep blueberries fresh longer
One of the best ways to keep blueberries plump and rot-free is to keep them dry for as long as possible, says Dr. Annis. “If you’re going to wash them, you’re going to want to do that right before you use them.”
If you wash berries before stowing them in the fridge, she says, you’re making it easier for whatever fungi might be present to grow and spread (we actually recommend holding off on washing for most fruits and vegetables). Of course, if you plan on freezing your berries, washing them is an essential first step.
The last thing to consider is what other fruits are being stored near your blueberries in the fridge. In addition to emitting small amounts of ethylene—a hormone that induces ripening—themselves, blueberries are also ethylene-sensitive, which means they’ll ripen and rot more quickly when stored near other emitters (like bananas and apples).
