Mold can grow on many things including food. For instance, you may see mold grow on bread. It may look black, green, blue, yellow or another color. It may also have a fuzzy appearance. Mold is a type of fungi, so its spores are frequently in the air. Bread provides an inviting home for the mold spores.
What Is Bread Mold?
Mold is a fungus in the same family as mushrooms. Fungi survive by breaking down and absorbing the nutrients of the material on which they grow, such as bread.
The fuzzy parts of mold you see on bread are colonies of spores — which is how the fungus reproduces. Spores can travel through the air inside the package and grow on other parts of the bread .
They’re what gives mold its color — white, yellow, green, gray, or black, depending on the type of fungus.
However, you can’t identify the type of mold by color alone, as the color of the spots may change under different growing conditions and can fluctuate during the lifecycle of the fungus .
Types of mold that grow on bread include Aspergillus, Penicillium, Fusarium, Mucor, and Rhizopus. What’s more, there are many different species of each of these types of fungus.
The Mold Spore.
Mold spores are microscopic plants that float on every breeze, inhabit every inch of earth and surround us everywhere we go. Some molds produce mycotoxins, which are dangerous poisons that can cause serious illness. Other molds are beneficial, breaking down diseased yard waste and providing building blocks for antibiotics, miracle drugs that have saved millions of lives. Molds helped scientists break the genetic code and today help researchers discover the effects of humanity’s “biological clock” and how it works. One of the most familiar forms of this filamentous fungus is the fuzzy green and gray growth that affects the foods we keep, particularly breads.
How to mold bread.
Once a spore finds a piece of bread in a dark, cool place where air does not circulate well, it sinks its little feet, called “hyphae,” into the spaces that make up the surface of bread. Mold spreads rapidly, forming the mycelium or mold colony. Clusters of hyphae, called “sporangiophores,” grow upward, forming the mature “conidia” that hold the spores and give each mold its distinctive color. When their cases break open, tiny spores go airborne until they find a hospitable place to land that is cool, damp, dark and has a good food supply, and then the process begins anew. The hyphae dig deep into the porous surface of the bread, working through it as well as over its surface.
Mold spores are the “seeds” cast off by mature fungi. They are everywhere, but they need the right environment to settle and grow. Aspergillus, Penicillium, Rhizopus and Neurospora crassa are a few of the thousands of mold spores that float around the kitchen looking for places to start colonies. Bread, particularly white bread, is an attractive place to land because it is high in starch, a substance that breaks down into sugars, which is a high-energy food for mold. Bread is also generally kept sealed in a bag, limiting air circulation and stays in a cool, damp, dark place like a refrigerator or bread box. These are prime conditions for development of mold colonies.
If the temperature is too cold, like in the freezer, the little spores will not be able to grow and will shrivel up. Mold cannot survive at high temperatures either, making baking a good way of destroying mold. Once the starches in bread begin to “set up,” however, it becomes a tempting treat for hungry mold spores. Because molds do not have chlorophyll like other plants, they are particularly aggressive feeders, so thousands of spores can cover a piece of bread overnight and millions in a few days.
Is It Safe to Eat Moldy Bread?
You may wonder whether the fuzzy spots of mold are safe to eat, can simply be scraped off, or whether the rest of the loaf is safe to eat if it doesn’t have visible mold.
Don’t Eat the Mold on Bread.
Some mold is safe to consume, such as the types purposely used to make blue cheese. However, the fungi that can grow on bread give it an off-flavor and may be harmful to your health.
It’s impossible to know what kind of mold is growing on your bread just by looking at it, so it’s best to assume it’s harmful and not eat it .
Additionally, avoid smelling moldy bread, as you may inhale spores from the fungus. If you have an allergy to mold, inhaling it could lead to breathing problems, including asthma .
Those with allergies to inhaled mold may also experience harmful reactions — including life-threatening anaphylaxis — if eating it in food. Still, this appears to be uncommon .
Lastly, people with weak immune systems — such as from poorly controlled diabetes — are vulnerable to infection from inhaling Rhizopus on bread. Though uncommon, this infection is potentially life-threatening.
Advises discarding the entire loaf of bread if it has developed mold .
Though you may only see a few spots of the fungus, its microscopic roots can spread quickly through porous bread. Therefore, don’t try to scrape off mold or salvage the rest of your loaf.
Some mold can produce harmful and invisible poisons called mycotoxins. These may spread through bread, particularly when mold growth is heavy.
High intake of mycotoxins may cause digestive upset or other illness. These toxins can also sicken animals, so don’t feed contaminated bread to your pets.
Furthermore, mycotoxins may negatively affect your intestinal health, possibly by altering the makeup of the microbes that inhabit your gut.
Bread Handling and Storage Tips.
Common mold spores generally can’t survive baking, but bread can easily pick up spores from the air after baking — for example, during slicing and packaging .
These spores can start to grow under the right conditions, such as in a warm and humid kitchen.
To deter mold growth on bread, you can :
▪️ Keep it dry. If you see visible moisture inside the bread package, use a paper towel or a clean cloth to dry the package before sealing it. Moisture encourages mold growth.
▪️ Cover it. Keep bread covered, such as when serving it, to shield it from spores in the air. However, to avoid soggy bread and mold, don’t package fresh bread until it’s thoroughly cooled.
▪️ Freeze it. Though refrigeration slows mold growth, it also makes bread dry. Freezing bread stops the growth without altering the texture as much.
Gluten-free bread is more vulnerable to mold growth, as it typically has a higher moisture content and limited use of chemical preservatives. For this reason, it’s often sold frozen .
How Does Mold Grow on Bread?”, sciencing.com
Is It Safe to Eat Moldy Bread?”, www.healthline.com