* Note: This is an abbreviated project idea, without notes to start your background research or a procedure for how to do the experiment. You can identify abbreviated project ideas by the asterisk at the end of the title. If you want a project idea with full instructions, please pick one without an asterisk.

Abstract

Have you ever bitten into a slice of bread only to find that it no longer seems fresh? Instead, it has the firm, undesirable texture that comes about when the bread is going stale. Chemically, what happens during the staling process? Can it be reversed (at least temporarily)? Do some background research to answer these questions and then apply those answers to one (or more) of the following experiments to find the optimal state to keep your bread fresh.

Experiment 1: What Temperature Keeps Bread Fresh the Longest?
Take slices of bread from the center of a single loaf and package the slices in their own individual plastic baggies. Put some of the packaged slices in the freezer, some in the refrigerator, and some at room temperature. Design an experiment to determine at which storage temperature the bread goes stale first. Hint: You'll have to come up with a way to reliably evaluate when a slice of bread is stale.

Experiment 2: Do All Types of Bread Go Stale at the Same Time?
Under identical storage conditions, compare how long it takes different kinds of bread to go stale. You can choose among heavy breads, light breads, mass-produced, and local bakery breads. Warning: This can be tricky! Before you start, you need to design a way to measure whether two very different kinds of bread have the same degree of staleness. Be sure to store the different breads in identical conditions.

Experiment 3: How Effective is an Emulsifier at Keeping Bread Fresh?
Manufacturers of most "mass-produced" bread incorporate emulsifiers in their recipes to increase the shelf-life of bread before it goes stale. Buttermilk and egg yolks in a homemade bread recipe can have the same effect. Perform background research to learn how emulsifiers work and identify specific ones. Using your background research, read the ingredients label of different varieties of bread to determine whether or not they contain emulsifiers. Or even better, you can make bread from scratch, with and without emulsifiers, but otherwise the same. (Making your own enables a better experiment because store-bought breads might differ in more than just the emulsifiers.) Compare how long it takes bread with and without emulsifiers to go stale. Be sure to store the different breads in identical conditions.

Bibliography

• McGee, Harold. On Food and Cooking: The Science and Lore of the Kitchen. New York: Scribner, 2004. pp. 541-542.

Variations

• For more science project ideas in this area of science, see Cooking & Food Science Project Ideas.

Last edit date: 0000-00-00 00:00:00