Eating Moldy Food: When It's OK, When It's Not

Even if you refrigerate promptly, moldy food is still a fact of life.

But is it safe to eat? Sometimes yes, and sometimes no. "The average person doesn’t know which mold is harmful," says Michael P. Doyle, PhD, the director of the Center for Food Safety at the University of Georgia, in Athens, Ga.

Mold can cause allergic reactions and produce toxic substances called mycotoxins and aflatoxins. This guide, adapted from the

USDA, can help you decide if a moldy food is safe to eat.

Throw it out.

If your hot dogs are moldy, you need to throw them out. Bacteria—which are invisible—may be growing alongside the mold.

"Mold grows more slowly than bacteria, so that’s why it may take several days or weeks for mold growth to develop," says Doyle.

Don’t risk it.

Keep it.

A thin, white coating gets the OK; anything out of the ordinary you’ll want to cut out.

“[In] some of the hard salamis, mold is actually added to produce a special flavor,” says Doyle. “In general those types of molds are considered to be safe.”

It’s normal for dry-cured country hams to develop some surface mold as well. So the ham should be safe to eat as long as you scrub the mold off first.

Throw it out.

If you see mold on a cooked casserole, throw it out. The surface mold may be just the tip of the iceberg.

With high moisture foods, mold can send filaments deep within the food, contaminating a larger amount of the food than is apparent to the eye.

Throw it out.

Leftover pasta also has high moisture content, so chances are the food is more spoiled than it looks.

Make sure to toss pasta at the first sign of any mold.

Keep it.

In general, it’s OK to cut the mold from hard cheeses, such as cheddar, that do not use mold as part of the manufacturing process.

"The rule of thumb is cut off as much as an inch, but I don’t do that because I’d lose most of my cheese!" says Doyle.

As long as you remove the mold with about a half-inch to an inch buffer you should be safe. Just make sure to keep your knife out of the mold so as not to cross-contaminate, and afterwards rewrap the cheese in a fresh covering.

Throw it out.

Bacon has high moisture content, and mold, if present, is likely to have spread beyond view.

It depends.

Cheeses like Roquefort, blue, Gorgonzola, Stilton, Brie, and Camembert couldn’t exist without mold, which is a vital part of the manufacturing process for certain cheeses. Still, not all mold is created equal.

"When there’s wild mold growing on the cheese we don’t know for sure what type of mold is growing," says Doyle.

If a soft cheese like Brie or Camembert has a moldy spot that doesn’t belong, throw it away. A harder cheese like Gorgonzola should be safe to use as long as you cut the moldy spot out.

Throw it out.

Soft foods like yogurt and sour cream are among the easiest foods for molds to spread throughout.

A small mold spot in a “semi-moisture or liquid product could more easily diffuse [toxins] into the product,” says Doyle.

Throw it out.

"Some molds may be able to grow at a higher salt content than your average bacteria," says Doyle, putting sodium-heavy lunch meats in the line of fire.

If you see any mold on deli meat, better to toss it than risk eating food that is likely contaminated below the surface, where you don’t see it.

Throw it out.

Sweet, sugary foods—like salty foods—welcome molds.

"Molds tend to be more adaptable than bacteria in many cases, and can grow in these types of foods that might have ingredients that would be inhibitory to general bacteria growth," says Doyle.

Plus, molds spread more easily through these soft foods.

Keep it.

A tough vegetable like a carrot can have a little mold but still be edible; mold has trouble penetrating deep into dense food.

Trim off about an inch around the mold, and then feel free to munch away.

Throw it out.

It can be frustrating to see mold take hold of leftovers that seem to have been properly stored.

But leftovers often have high moisture content, which provides a friendly environment for bacteria and molds.

There may also be additional mold under the surface that you don’t see.

Throw it out.

You wouldn’t even think about eating a mold-covered strawberry, right?

Still, something like an orange may seem like fair game. Unfortunately, the tough rind doesn’t offer as much protection as you may think.

Even if you don’t see it, mold can permeate the skin and spread quickly through the fleshy insides.

"Sometimes the mold will just grow on the surface," says Doyle, "but if you eat it you may taste a little moldy taste."

Throw it out.

If there were a most-likely-to-get-moldy award, bread would be the winner.

If one slice out of an entire loaf has a little spot of mold, it’s probably fine to use the slices farthest away from the incriminating spot. But maybe not.

"There may be some mold growth you just don’t see," says Doyle. Porous foods like bread, muffins, cakes, and other baked goods also allow easy penetration of molds below the surface.

Throw it out.

The moisture content is higher in these types of soft cheeses, so they are more likely to allow mold to penetrate deep into the product.

Mold on one slice or a small piece of shredded cheese is likely to have spread to the entire package, so don’t try to save the bits that don’t have any visible mold.

Throw it out.

Peanuts are among the foods most likely to grow the molds that produce the most dangerous toxins.

"Based on past history, we know that peanuts could contain the molds that produce aflatoxins," says Doyle. Ditch any nuts or nut butters with even a trace of mold.