Comparing the Rate of Mold Growth on Different Breads
Author(s): Aldo-Rafael Cos
Growth & Development Experiment 
SED 695B; Fall 2005

Research Question:

Which type of bread grows mold the slowest?

Standards addressed:

Grade 8:

5. Chemical reactions are processes in which atoms are rearranged into different combinations of molecules.
a.
Students know reactant atoms and molecules interact to form products with different chemical properties.
Independent variable
Dependent variables
Controls
Series
Time (days)

Rate of mold growth

 
Temperature, humidity, light

Wonder

Wheat

Rye
Materials
Procedures
Containers, 3 brands of bread. Jewish Rye bread, Wonder Bread (white), Sara Lee Wheat bread, dropper, transparent grid, digital camera
• Buy materials
• Cut out even portions of bread
• Place each type of bread in a container
• Put a few drops of water on each bread. Seal container
• Keep containers at room temperature with a moderate light source.
• Observe containers daily. Take photo of each bread.
• Place a transparent grid on photo to measure mold growth
• Calculate the growth per day and record.
• Make graph
• Report on your findings
 
 
Day
Wonder Bread
Wheat Bread
Rye Bread
10/13/05
10/15/05
10/18/05
10/20/05
10/23/05
10/25/05
10/27/05
11/01/05

 

  

 

  

 

  

Conclusion: The mold grew slowest with the Wonder bread. The other breads grew mold at a much faster rate. This is in part due to the various preservatives added to Wonder bread.

Digitally Overlapping Grid on Photos
1. Open your photo using Photoshop Elements.
2. Go to view, and select ruler
3. Go to view and select grid
4. Hold down shift-apple-4 (for mac)
5. Select the photo and save as a jpg.

Bread Ingredients

Wonder Bread:

Wheat Bread:

Rye Bread:

 

  

References & Links:

FAQ about Molds (Office of Environmental Health and Safety)

Bread Mold Fungus

Mold Isolation, Cultivation, and Identification