Bread Mold Experiment

3.8 based on 298 ratings
Updated on May 6, 2014

There's nothing worse than finding a moldy piece of fruit in the bottom of a bag. Who ever thought that moldy bread would lead to a the development of modern antibiotics? More cultures that you might know used mold to help prevent infection. Poultices of moldy bread were used in ancient Egypt, ancient India, and ancient Greece, and penicillin, an important antibiotic, is derived from mold spores.

Mold spores are everywhere just waiting for the right environment to grow and multiply in. But what is the best environment for them? Is it cold or warm? Sunny or dark? This bread mold experiment will help your child find out, while developing important hypothesis-making and experiment-designing skills.

What You Need:

  • 3 pieces of bread
  • 3 resealable plastic bags
  • Permanent marker
  • Water

What You Do:

  1. Put bread in all three bags.
  2. Take one bag and put it in a dark place. Place the next bag in the refrigerator. Place the last bag in a sunny area. Make sure each bag is sealed tightly. Label them with a marker.
  3. While you wait for the results, work with your child to develop a hypothesis as to what will happen to each bag of bread. Think about where mold grows naturally. What conditions does your child think are conducive to mold growth in nature?
  4. Check each bag daily to record any changes you see, and compare the results with your child's hypothesis.

Did You Know?

  • Different types of mold grow in the dark versus the light, and cold versus warm temperatures. 
  • All mold is dangerous to eat. If you ever have a slice of moldy bread it is recommended that the whole loaf be thrown out. Mold spores are microscopic and are already all over the entire loaf even if colonies haven’t developed yet.

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