Is It Safe to Eat Moldy Bread?

Jan 27, 2024

Spoiler alert: If you don't want to risk getting sick, just throw it out.

Novella Lui is a registered dietitian and a nutrition and health writer. She is passionate about supporting others in building healthy relationships with food by sharing practical and easy-to-follow tips. Novella combines her interest in providing evidence-based nutrition and health education with food and culture through creating consumer-focused content for brands and publications. As a foodie and a globetrotter, she loves to seek new flavors and explore different cuisines. In her spare time, you can find her looking for hidden food gems and spending time outdoors hiking local trails.

Maria Laura is EatingWell's senior nutrition & news editor. As part of the nutrition team, she edits and assigns nutrition-related content and provides nutrition reviews for articles. Maria Laura is a trained dietitian, almond butter lover and food enthusiast with over seven years of experience in nutrition counseling.

Bread is a staple in many homes. Whether you're known for making Instagrammable avocado toast or like to assemble New York deli-worthy sandwiches, it's likely you keep at least a loaf in your kitchen at all times. Maybe you even keep a sourdough starter in your fridge so you can bake your own loaves. No matter how much bread you eat, chances are high that you've probably forgotten about a loaf only to find it dotted with spots of mold. And it probably made you wonder—should I cut off the moldy parts of the bread and eat it? Read on to find out if moldy bread is ever safe to eat, how long bread lasts, and the best ways to keep it fresh.

Molds are fungi that may or may not be visible to the naked eye. If you see mold on food, that's just part of the story. That likely means that there's a large root network in the food itself: think of it like a network of blood vessels. The visible mold is made up of the mold's stalk rising up from the surface of the food with fuzzy spores attached. If you took a look at that moldy piece of bread under a microscope, the mold would look like little mushrooms popping up from the surface

Several types of mold grow on bread, including Penicillium, Fusarium, Aspergillus, Rhizopus and Mucor. Each kind of mold also has its own varieties, and each fungus species has a different spore color. To complicate things, the spores' color changes based on the fungus' life cycle and the surrounding environment.

Molds thrive in a moist environment, and mold spores spread through the air surrounding the medium it grows on—like that loaf of bread you left in your breadbox for too long.

The simple answer is, no, please don't eat moldy bread. Whether the loaf of bread has one spot of visible mold or multiple ones, the bread is unsafe to eat. According to the USDA's Food Safety and Inspection Service, when you see molds growing on bread, it is likely that the root of the mold has infiltrated much of the loaf, no matter if the loaf is whole or sliced.

With so many types of molds in the environment, there is no way to identify the type of mold (unless you have a science lab at home!) and whether the mold present is poisonous. So it's better to err on the side of caution and not to eat moldy bread to avoid getting sick.

Cutting off the mold you can see doesn't mean the bread without visible mold is safe to eat either. Since the root of the mold is deeply entrenched into the bread, with microscopic threads penetrated throughout, you can assume that there is a lot more mold than you can see. It is best to throw out the bread.

Molds on bread may also produce a type of harmful toxins called mycotoxins. You may or may not get sick from eating moldy bread, but you can assume that the more moldy it is, the higher your chances are of getting sick. If you do eat moldy bread, you risk experiencing unpleasant symptoms, including nausea, vomiting and diarrhea.

In particular, young children, people over 65 years old, pregnant individuals and people with a weakened immune system should not eat moldy bread. Members of these groups could get seriously ill when they experience food poisoning.

Furthermore, according to the Centers for Disease Control and Prevention, people with poorly managed diabetes, and other conditions, may be more prone to getting infected by a rare but severe condition called mucormycosis after inhaling the spores of Rhizopus, a mold commonly found on bread.

More importantly, eating foods contaminated with mycotoxin may negatively impact gut health by destroying the beneficial bacteria and may elevate the risk of liver cancer, per a 2018 review published in Frontiers in Cellular and Infection Microbiology.

According to the USDA'S Foodkeeper App, homemade bread can last up to three to five days in the pantry and two to three months in the freezer. To extend its freshness, using cloves, cinnamon and vinegar as part of the ingredients may prevent or delay mold growth, but obviously could change the bread's smell and flavor

Commercial bread, like a loaf packaged in a plastic bag that you'd find in the bread aisle at the grocery store, can last for about two weeks at room temperature, two to three weeks in the refrigerator and up to five months in the freezer from the date of purchase. Why can they last so much longer? These loaves are made with preservatives that inhibit mold growth.

If you make homemade bread or buy a loaf fresh from a bakery while it's still warm, be sure to let it cool completely before covering it so you don't trap excess moisture on the loaf. And if you grab a slice of bread and discover moisture on the loaf, pat it dry with a clean towel or paper towel.

Even if it hurts to do so, moldy bread should be thrown away because it's unsafe to eat, no matter how little mold is on there. Molds produce toxins that not only cause food poisoning but can also impact our health. If you only see a little bit of mold on a loaf of bread, that doesn't mean there isn't more that you can't see—it's likely that all of the bread is contaminated. Commercially baked loaves of bread have preservatives that inhibit mold growth, so they last longer than homemade bread. Use your freezer to extend bread's shelf life, and when in doubt, throw it out.