Is It Dangerous To Eat Moldy Bread?

I love bread. There’s always a loaf sitting in a bread basket on my kitchen counter. Sometimes I forget about it for a few days and when I reach for a slice, inevitably it’s moldy—there are a few things more disappointing than moldy bread. I’m often tempted to toss the moldy slices and keep eating the rest. But is that safe? Here’s what the experts say about eating moldy bread and the best way to keep it fresh for longer.

What Exactly Is Mold?

Molds are teeny tiny fungi that can grow and flourish on plants, animals, and foods like bread. You might only see these white or green spots on the surface of bread, but mold branches out with roots deep inside, below the surface—that’s the part you don’t see.

Mold thrives in warm, humid conditions, but can also live in cool environments, like the inside of a refrigerator. It has been shown to cause respiratory issues and allergic reactions. Some molds even produce toxic substances called mycotoxins, which can make you very sick.

The 4 Factors That Cause Your Bread to Mold

According to Nichole Dandrea-Russert, MS, RDN, there are four factors that can cause bread to mold: air, moisture, time, and temperature. The longer it’s exposed to oxygen in the air, the more likely bread will mold. It may also become moldy faster in humid conditions, due to the extra moisture in the air. 

“Bread stored at room temperature will mold more quickly since mold spores grow between 40°F and 140°F,” says Dandrea-Russert. “Bread’s shelf life is approximately three to four days at room temperature. Mold may grow if left out for longer than that.” According to research documented in the National Library of Medicine, bread with added chemical preservatives stay fresher for longer than those without preservatives by preventing or minimizing mold growth.

Is It Safe To Eat Moldy Bread?

I would never eat the actual moldy parts of the bread, but is it OK to cut off the visible mold and eat the rest of the loaf?

The problem is that mold penetrates deep into foods. For some foods, like hard cheeses and firm produce, it’s hard for mold to spread its roots. In those cases, it’s OK to cut out the moldy spots, but not with bread.

Dandrea-Russert says she never eats bread when there’s mold anywhere on the loaf.

“First, molds can produce mycotoxins, which can spread easily and are toxic to human health. Second, I know that I am allergic to mold and I also have asthma. Knowing that mold can trigger allergy and asthmatic symptoms, I steer clear away from it,” she says. “Finally, there is research showing that certain types of mold that grow on bread may disrupt gut health. For that reason, when I see mold on bread, it goes into the compost.”

The Best Way To Store Bread 

To keep your bread from molding quickly, store it in an airtight container or, better yet, a bread box. A bread box is designed to have ideal air circulation that prevents the inside from becoming too humid or hot. Just make sure to remove the bread from its packaging before you place it in the bread box.

“If you want to extend shelf life and prevent mold from growing quickly, consider storing bread in a brown paper bag, linen bag, bread bin, or, especially if you live in a humid environment, store slices of bread in the freezer,” says Dandrea-Russert. “You can separate bread slices with unbleached parchment paper so they don’t stick together.”