How to Tell if Bread is Moldy

It’s not everyone’s dream to wake up and munch on a piece of moldy toast. To avoid these situations, you need to know how to tell if bread is moldy. The good news is that it’s easy to spot the fuzzy, colorful stuff most of the time. The only issue arises when working with flour-coated bread.

Hey, there! My name is Michelle, and I would be lying if I told you I have never accidentally eaten moldy bread. Granted, it was on a tortilla rather than a piece of bread, but needless to say, it was repulsive. I didn’t get sick from the mold – I got sick from the thought of sinking my teeth into it.

With that in mind, it’s important to know how to tell if bread is moldy, and that’s what we’re here to discuss today. It might not be the most glamorous topic, but it’s something everyone should know – bread baker or not!

Let’s talk about everyone’s favorite fuzzy friend – mold.

What is Bread Mold?

Before we look at the key indicators of bread mold, let’s first dive into what bread mold actually is. Mold is essentially just a fungus that attaches to a food source, such as bread. Over time, colonies of mold break down the bread and absorb the nutrients. 

Five types of mold grow on bread, and each has its open realm of potential species. Of the five mold types, there are:

  • Aspergillus
  • Penicillium
  • Fusarium
  • Mucor
  • Rhizopus

How to Tell if Bread is Moldy

The easiest way to tell if bread is moldy is to simply look at it. While there are five different types of mold (and even more sub-species within each type), it’s almost impossible to know which mold is growing on your bread.

This is due to two important things: 

  • Mold color can change based on the growing conditions
  • It is also altered throughout the lifecycle

So, don’t think you will be able to point out which kind. Regardless of the “type” of mold infecting your bread, you can look for these colors:

  • White
  • Yellow
  • Green
  • Gray
  • Black

The spots will likely have a fuzzy and undesirable appearance. Who wants to toss an oddly-colored fuzzball into their mouth? Certainly not me!

Learn more about the different types of mold on bread here (there’s also a handy video you won’t want to miss).

How to Tell if It’s Mold or Flour

A lot of the time, bread mold is white or at least begins that way. Simple, right? Not exactly. Some bread, such as artisan bread, is topped with a coat of flour. It provides a desirable rustic appearance that is as easy on the eyes as it is on the palette.

While enjoyable and delicious, flour-dusted bread also poses one major issue: it can be hard to decipher whether the “white” is flour or mold. What’s an artisan bread lover to do? 

Luckily, you can perform a few tests to see whether the white spots on your bread are flour or mold. Here’s how.

  • Try to flake it off. The flour will have a powdery texture that will brush off the bread with ease. If you try to flake off white mold, it will come off in chunks instead.
  • Look at the color. Yes, flour and mold are both white, but they’re not the same “shade”. The flour will have a bright white appearance. Mold will have an off-white shade that is sometimes tinged with green or blue.
  • Wait for growth. If it’s flour, it’s not going to continue spreading across your bread loaf. But if it’s moldy, you can wait a few days, check back, and see that the new white-ish substance has clearly expanded.
  • Check the smell. If you smell bread, it basically smells like nothing (unless it’s flavored, of course). If the bread has a musty or old scent, it’s likely due to mold spores growing on the bread. Be careful sniffing, though! Mold can cause allergic reactions if inhaled.


You want to avoid the fuzzy stuff that can be colored, whether it’s a slight greenish hue or entirely gray. If you still want to learn more about how to tell if bread is moldy, check out these frequently asked questions below.

Can you always see mold on bread?

Not always. However, you can be 100% sure that if you see a single spot of mold on one slice of bread, it’s going to be riddled through the rest of your bread loaf. Even if it’s just one dot of mold, it’s best to throw out the entire loaf and buy a fresh one. More on this here.

Is white stuff on bread mold?

Maybe yes, maybe no. If it’s bread that has a flour-coated top, it might not be. The best thing to do is to perform the four tests I shared above. Try to flake it off, double-check the color, check the smell, and wait to see if it spreads.

Is bread ok if it’s not moldy?

Even if your loaf of bread is old, it is safe to consume as long as there is no mold growing on it. Just note that it might not be as good as a fresh loaf of bread. You can still use old, stale bread in various recipes such as breadcrumbs and bread pudding!

What does mold look like on brown bread?

Mold appears the same on brown bread as it does on white bread. However, it may be a bit tougher to spot. So, inspect your bread thoroughly before consuming it. While white or green mold is highly visible, a darker gray or black mold might not be so simple to see.

Final Words

Mold on bread? Yup, it’s gross. But luckily, it’s easy to spot. Mold appears like a fuzzy, colorful contraption on bread. It differs from flour coats because it is usually an off-white shade and flakes off in chunks.

Have you ever noticed mold on your loaf of bread? What did it look like? Share your moldy stories with us!

About Michelle
I have been a lover of sweets since day one. This led me on a self-taught baking journey starting at the age of 13. It's been over 10 years since the start of my baking adventures, and I’ve learned a lot along the way. Now, people rave about my delectable treats, whether it’s a chocolate cake or a strawberry crepe.

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