Have you ever left a loaf of bread on the counter, only to find it covered with dark, fuzzy spots a few days later? That’s black mold at work – a particularly unsettling and unwelcoming guest who thrives in our kitchens’ forgotten corners.

With its sinister appearance, black mold can turn a fresh product into something inedible. Bread can grow mold relatively quickly, making it essential to consume the food within five to seven days. Here’s a look at how bread develops black mold.

What is Mold?

Similar to mushrooms, mold is a type of fungus that thrives both indoors and outdoors. Although mold spores resemble tiny plants, they are neither plant nor animal. Rather, mold is a living organism that feeds off of decaying matter, such as rotting wood, or even food, such as bread. When these spores land on a damp surface, they can grow and form colonies, which are often visible as fuzzy or slimy patches in a variety of colors such as green, black, white, or blue.

Mold spores are nourished by three food sources: moisture, organic matter, and oxygen. Damp areas are notorious for harboring mold colonies since they provide a constant supply of moisture that steadily feeds the spores. Organic matter provides a food source for mold spores, creating a consistent food source. While some molds play a beneficial role in nature by breaking down dead organic matter, others can spoil food, damage property, and pose health risks.

How Does Black Mold Grow on Bread?

Bread molds are known to colonize different types of breads. The sugar and carbohydrates contained within loaves of bread offer ample supplies of nutrients to the spores. These rich organic materials can spur mold growth within a short span of five to seven days.

The species of mold that develops on the bread depends on the type of spores that linger in the immediate environment. Rhizopus stolonifera, also known as black bread mold, is one common mold that affects bread. This type of mold grows everywhere on the planet.

Moist conditions are ideal for the growth of black bread mold. Due to this reason, black bread mold will grow on wild fruits and vegetables, too. As the mold consumes the organic material, it causes rotting. Black bread mold is known to even kill plants.

As it starts to grow on the surface of bread, black bread mold appears as velvety blue or green patches. When the bread is left untouched for days, these unsightly blue and green patches develop centers that are noticeably black and splotchy—hence its name, black bread mold. The mold may or may not develop a musty smell as well.

How Quickly Does Black Mold Grow on Bread?

Exposure to moisture and air can trigger black bread mold growth. Organic white bread does not contain preservatives, which means black bread mold will grow on these loaves the fastest. When left at room temperature and exposed to moisture, white bread can develop mold in five days.

The speed at which black bread mold grows on loaves also depends on the acidity of the bread and its moisture content. Most breads are non-acidic and contain a pH level of seven. Sourdough bread has a higher acidic level in comparison to white bread, so mold develops more slowly.

Bread may seem dry, but it contains a large amount of moisture. Moisture from the inside of baked bread travels to the outside. The crust may become noticeably softer, for instance. When storing bread in a plastic bag, moisture will be evident; and mold growth can occur.

Furthermore, the temperature at which the bread is stored plays a large part in how fast a loaf will develop black bread mold. Leaving a loaf of bread exposed to moisture and air will invite a flurry of mold spores, especially considering that mold thrives in humid environments.

A room temperature of 86 to 98 degrees Fahrenheit can spur certain types of mold growth. However, storing bread in the freezer at 32 degrees Fahrenheit will stop the chances of mold growing on the loaf. Freezing bread prevents mold growth altogether.

Is Eating Bread With Black Mold Harmful?

Taking a small bite out of a moldy slice of bread is generally not harmful. However, severe reactions can develop in individuals who are allergic to mold. Upon inhaling the spores, the mold can trigger respiratory issues, especially in people suffering from asthma or immune diseases.

Consuming larger amounts of bread contaminated with black bread mold can cause severe illness. An individual who ingests a large amount of moldy bread can experience an upset stomach and be exposed to mycotoxins. Mycotoxins are harmful when inhaled or eaten, potentially causing fatigue and rashes.

When noticing black bread mold, it is wise to discard the entire loaf. Mold spores are microscopic and difficult to detect until they grow into larger clusters. Mold can also grow deep roots without detection; so, avoiding sickness to varying degrees is best done by throwing out the moldy bread.

Bread mold can also generate unpleasant odors when left in a trashcan inside the house, read How to Remove Odors from the Trash Can for proper solutions to remove the odors.

How is Black Mold Prevented on Bread?

As previously mentioned, freezing bread prevents mold growth. Additionally, consume the bread within two to three days—before mold has a chance to grow. Avoid slicing the bread, which accelerates the rate of spoilage. Also, store the bread in a dry bread box or paper bag to reduce moisture buildup.

Mold colonies are notorious for spreading rapidly, which is why it is important for homeowners to immediately address a mold problem. You must call a professional who provides quality mold removal services to residential homes and commercial properties.

Professional mold cleanup technicians use high-tech equipment to locate all mold growth within the property. Upon finding both hidden and visible mold growth, they contain the areas to prevent contamination to other parts of the building. Using advanced methods, specialists eliminate all mold growth.

Structural materials may be permanently damaged by the mold colonies. Mold removal technicians also provide restoration services to affected areas and remove components that are beyond repair. A key part of mold remediation is to fix the moisture source that triggered the mold invasion.

Delays in stopping a mold invasion can lead to structural damage to building components. Mold spores eat away at organic materials, including drywall, causing the weakening of building materials. Health problems, from itchy skin to watery eyes, can also develop in the building’s occupants.

When you need help to remove a mold problem, call a professional for skilled mold cleanup techs to ensure your building is mold-free.

About Vince Sandri

Vince Sandri is a content writer and blogger with more than 12 years of experience. His expertise is in creating content related to disaster restoration, including information about preventing and reacting to natural disasters like flooding, water damage, fire and smoke damage, mold growth, storm damage and more.
Vince has been the main contributor to RestorationMasterFinder.com since 2014. Over that time, he has written numerous service pages and blogs for disaster restoration providers featured on RestorationMasterFinder.com. Vince has done extensive research and covered a wide range of topics relating to disaster restoration to help homeowners, business owners, and property managers better protect their property. He understands the problems that disasters like flooding, fire, smoke, and mold can cause as well as the best ways to respond to these issues to limit the damage.
Vince completed his Bachelor of Arts degree at Aurora University and his master’s degree at DePaul University. He has been writing SEO website pages, blogs, and press releases since 2012. Vince is also a musician and can be seen playing in the Chicago, IL area.