How to Do Successful Science Fair Projects

Moldy Bread Experiment    

                                                                                                                                                                   The Moldy Bread Experiment: Growing Bread Mold  

The Microscope for the Moldy Bread Experimentmoldy bread experiment is easily expanded into a very substantial project by increasing the number and variety of variables. Bread mold is inexpensive to grow and may yield valuable scientific information. Follow the instructions outlined below and hopefully your experiment with bread mold will result in a winning science fair project.

Bread mold is classified as a type of fungus. Types of bread mold that are often found are Aspergillus, Fusarium, Monascus and Penicillium. Before you begin this experiment you may want to review the concepts described in the Scientific Method
 Note: Some bread molds are toxic: inform your parents of this fact before starting to work on this project.


Project Title
The Effects of Various Environmental Factors on the Growth Rate of Bread Mold. 

Light, temperature, humidity and salt influence the growth rates of bread mold.

Five (5) slices of white bread

Five (5) small sheets of Saran wrap or 5 small Ziploc-type sealable bags

One (1) small paper bag

One (1) small piece of cloth, approximately 2 inches by 2 inches square

One (1) ink pen 

Five (5) small adhesive labels 

Procedures for the Moldy Bread Experiment

  1. Write “SALT” on the label for the first sealable bag; sprinkle salt on one piece of bread, insert into the bag and seal. 

  2. Write “No Salt/Light/Dry/Room Temp.” on the label for the second bag and insert bread into the bag and seal.

  3. Write “No Light” on the label for the third bag; insert bread into the bag and seal: place sealed bag into the paper bag.

  4. Write “Humid” on the label for the fourth bag; insert dampened cloth and bread into the bag and seal.

  5. Write “Cold” on the label for the fifth bag; insert bread into the bag and seal; and place the bag into the refrigerator.

  6. Examine the samples after 5, 10, 15, 20, and 25 days and note the percent coverage for each slice of bread.
  7. For a larger project, repeat the experiment for five cheese slices, five orange slices and five potato slices.  

Results of the Bread Mold Experiment (Fictitious Data)

                              --------------------Bread: Percent Coverage--------------------- 

   5 Days  10 Days  15 Days  20 Days   25 Days
Salt   10% 10%   10%  10%  10%
No Salt  10%    10%   10%  10%  10%
Light   10% 10%  10%  10%  10%
No Light   10% 10%  10%  10%  10%
Humid   10% 10%  10%  10%  10%
Dry   10% 10%  10%  10%  10%
Cold   10% 10%  10%  10%  10%
 Room Temp.  10% 10%  10%  10%   10%


You should be able to make the following types of statements. 

Salt decreases the rate of the growth of bread mold after 25 days by x%. 

Bread mold grows y% faster in darkness than it does in light. 

Humidity has a greater influence on growth rate of bread mold than any of the other tested variables.

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