Suface Microbiology and Cheese Science Fair Projects

Cheese and Mold

You may not know it, but mold is a critical part of making cheese. The mold is what cures the cheese and what gives it is texture and flavor. The longer a cheese is exposed to a mold the sharper its flavor becomes.

PURPOSE

The purpose of this experiment was to compare the amount of mold growth on three types of cheese (American, Swiss, and cheddar).

I became interested in this idea when I found mold all over the cheese in our refrigerator and was concerned because we had just bought the cheese. I wanted to find which cheese to buy to avoid repeating the problem.

The information gained from this experiment would help people know which cheese to buy for long term use.

HYPOTHESIS

My hypothesis is that American cheese will support more mold growth than the other varieties.

I base my hypothesis on World Book Encyclopedia, which says, "The more moisture the cheese has, the softer it is." This means soft cheese is moist and moisture is what mold needs to grow according to many books I read. American cheese is the softest out of American, Swiss, and Cheddar.

EXPERIMENT DESIGN

The constants in this study were:

• The amount of cheese.
• The storage of cheese slices in individual zip-lock bags.
• The kind of mold used to inoculate the cheese.
• The amount of mold spores inoculated on the cheese.
• The temperature, light, and humidity in the incubation environment.

The responding variable was the rate the mold grew on the cheese.

To measure the responding variable I used a transparent grid sheet to determine the approximate number of square centimeters of mold on the cheese each day.

MATERIALS

Surface microbiology cheese science fair projects continue at cheese micro science fair projects.