A science experiment to determine whether mold grows faster on bread or cheese offers that fun, "gross-out" factor that attracts kids to science. Though the premise of the experiment might sound silly, it's a good way to encourage students to use the scientific method, flex their brains and have fun while learning.
Setting It Up
You don't need to do anything special to the cheese or bread to grow mold. Mold spores are present everywhere, so it will simply grow on the cheese or bread that is left out. For an accurate comparison, according to Education.com, you'll need to keep the bread and the cheese in the same location, so that it is at the same temperature. Keep it in a designated place, though, so no one accidentally eats your experiment. Students should state a hypothesis as you start the experiment.
Your experiment might be more interesting if you compare the growth of mold on bread and cheese under different circumstances. For example, you might look at mold growth at room temperature versus mold growth in the refrigerator, or whether foods that are uncovered will mold faster than those that are covered. You might also try different types of breads or cheeses. No matter which variables you choose, place the bread and the cheese under the same conditions.
Carrying Out the Experiment
Take a picture of the bread and cheese at the start of the experiment. Each day, check them for mold and take another picture. It's likely to take several days for the mold to start to grow, but you don't want to miss the first little dot, proving which food grows mold faster. If you desire, continue the experiment a few days past the initial mold sighting, to see if the "winner" will continue to mold more quickly.
Your presentation should include a discussion about what mold is and why it grows on food, the details of your experiment, your hypothesis and your conclusion. Because the visual is so important to this idea, include photos of the bread and cheese at all stages of molding. If you have the capability, consider creating a stop-motion film of the mold growing by putting your daily photos into a video.