What Foods Grow Mold?

We’re calling all little scientists for a food mold experiment! With our printable observation sheets and our fun project, your kids will get a first look at how foods grow mold.

  • By Jess Dang
  • May 15, 2017

Mold might look a little scary but it’s a natural part of the food lifecycle. When foods are in their natural state (meaning no chemicals or preservatives have been added to them), mold helps them rot and indicate that they’re no longer good for us to eat. However, rotting food still has lots of nutrients. If you compost it, it can be returned to the soil to provide nutrients for other living things.

Unlike plants, molds don’t grow from seeds and they don’t know how to make their own food. Instead, they grow from spores. These spores land on food and replicate by breaking down that food and feeding on it.

There are more than 100,000 different types of mold and they grow differently on different types of food. Give your kids a little introduction about mold with this food experiment, where they can examine how foods grow mold.


  • Types of food – We recommend selecting at least 5 types of food, with at least 2 of them being bread and 1 being a processed food, such as chicken nuggets or a packaged food.
  • Ziploc bag – You’ll need 1 Ziploc bag for each type of food you plan to observe.
  • Permanent marker or masking tape + marker – You’ll need something for your kids to label the items in the bags.
  • Observation sheet – We’ve created an observation sheet for you to print out and your kids to write their observations.
  • Pen / pencil – Your kids will need a writing instrument to record all of their scientific findings!
  • Ruler and / or magnifying glass – For measuring and getting up close to the mold!

Directions (For Kids)

1. Label your bags

Label your bags with what you plan on putting into each one. For the bread, we recommend you label one bag “Bread – Dry” and the other bag “Bread – Wet”.

2. Place Food into Bags

Place food into their labeled bags and then seal tightly. For the bread, sprinkle one piece of bread with just a bit of water and place it into the bag labeled “Wet.” Place the dry piece into bag labeled “Dry.” You’ll then be able to see if water has an effect on mold growth.

Dip the other ingredients in water before putting them in their bags.

3. Observe & Record

Follow the instructions on your Observation Sheet to record what you see at the time intervals suggested. You might want to have a parent help you set alarms so you don’t forget!

Some suggestions for your observations:

  • How many spots of mold do you see?
  • What color is the mold?
  • How large is the largest spot of mold you see? (You can use your ruler for this)
  • What does the mold look like close up? (You can use your magnifying glass for this)

When your kids are finished with the experiment, ask them what their conclusions are about how foods grow on mold. If you guys have taken photos along the way to track the progress, share with us on Instagram or Pinterest with hashtag #KidsFood. We’d love to see your little scientists’ projects!

If your kids are looking for more ways to experiment and play with food, check out our other kids activities in our #KidsFood series:


How Do Plants Absorb Water?

Turn your kids into little scientists and teach them what happens when they water plants! Our fun project will allow… Read more.


How to Make Homemade Play Dough with Food Ingredients

Make homemade play dough with your kids for a fun activity, and give it a twist by using food ingredients… Read more.


How to Make Fruit & Veggie Stamped Tea Towels

Add some meaning and color to your kitchen space with food stamped tea towels made by your kids. Read more.

We put together this #KidsFood series, so that kids can get creative and exercise their artistic and investigative skills during the summer. These summer activities (and more to come!) will teach your kids more about food and keep them entertained while they’re at it.

Bonus: You’ll probably have a lot of fun and learn a lot as well!

As always, we’re here to help you live your best life in the kitchen and provide delicious memories for you and your family. Join our cooking community by signing up for our newsletter below, and we’ll send you great cooking tips and resources that will help you raise your kitchen IQ and cook with confidence.

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