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Bread Mold Experiment

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This post is part of the 31 days of creative STEM activities for kids series.

For today’s version of science experiments for kids, we decided to go classic with the bread mold experiment.

Although not as flashy as some of our other classic science fair projects, it was probably more educational than some others.

The students enjoyed seeing how long it took for mold to grow on various forms of bread.

In addition to just being a classic experiment, the bread mold experiment also makes a wonderful gross science experiment or Halloween science experiment!

The bread mold experiment is a classic science fair project for elementary that every kid should try! It's so easy and can be done in just a few days.

Classic Bread Mold Experiment for kids!

Follow along with these instructions to make your own version of the bread mould experiment!

Bread mold science project science:

Our experiment was simple. We placed bread in various conditions (we had dry dark, dry light, wet, open, and in a closed bag) and Monkey came up with a hypothesis for which piece of bread would mold first.

She predicted it would be the bread we placed in the paper bag in the pantry.

Bread mold experiment hypothesis

Kids should come up with their own hypothesis for the mold experiment. Have the children create a hypothesis something like this:

  • Bread with preservatives will take longer to mold
  • Bread in a sunny location will take longer to mold
  • Warm bread will mold faster
  • Wet bread will mold faster
  • Bread will mold faster in the open air than in a plastic bag
elementary stem challenge cards

Mold facts for science projects

When doing your bread mold science fair project, here are some fun mold facts for kids to include:

  • Mold is a type of fungus.
  • Mold grows in the shape or multicellular filaments called hyphae.
  • Mold grows from spores that float in the air.
  • There are thousands of types of mold, some good and some bad.
  • A lot of cheese and antibiotics are created with a mold as a base.
  • Mold is usually fuzzy.
  • Mold is considered a single organism.

Doing a science fair project? Check out the complete list of Science Fair Projects for Elementary!

Follow along with these instructions to make your own version of the bread mould experiment!

What you will need for the bread mold experiment:

  • Bread (fresh bread from a bakery will produce much faster results than bread with preservatives)
  • Various bags
  • A permanent marker to label each piece of bread
stem challenge worksheet

If you like this activity, you’ll also like these gross science experiments and Halloween STEM activities.

Bread mold science fair project directions:

Divide your bread into as many pieces as you want to test. We used around five pieces.

We only put water on one of our bread pieces, but for the best “scientific” results, you should put water on one piece in a dark place and one in a light place.

In all, we had:

  • Bread in a plastic bag in the light
  • Bread in a plastic bag in the dark
  • Bread in a paper bag in the dark
  • Bread on a paper plate with no bag
  • Wet bread in a plastic bag

My kids thought the dry bread in the paper bag would mold first.

You can take this project further by measuring how much mold is on each piece of bread after a certain number of days.

We just wanted to see which bread piece would mold first, so we did not do any mold measuring.

moldy bread science fair project

Bread mould experiment results

It took about two days for the first mold to show up- which was on the wet piece.

We waited weeks for any mold to show up on any of the other pieces, but it didn’t. This is why we recommend using fresh bread without preservatives.

We finally gave up on waiting for any more mold to grow and threw it out.

Looking for an easy science experiment with dramatic results? The bread mold experiment requires few supplies and is easy for kids of all ages!

The kids were surprised that the wet bread grew mold first, but she thought it was interesting that mold grows faster in damp, warm conditions.

After observing the results, I had the kids fill out a STEM reflection worksheet.

elementary stem challenge cards

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