Experiment: Defrosting Sandwich Bread
Freezing sandwich bread to keep it from going stale is a common practice. What is the best way to defrost the bread?
We thought that removing slices of bread from the freezer and letting them thaw at room temperature would be the best approach, but our assumption was wrong. After having a conversation with our science editor and performing a few experiments, we realized that by leaving the bread at room temperature, we would be submitting it to an environment that would actually stale it.
As frozen bread warms, its starch molecules begin to form crystalline regions, which absorb the water in bread. The process, called retrogradation, will eventually produce a dry, stale texture. The best way to thaw frozen bread is to place the slices on a plate (uncovered) and microwave them on high power for 15 to 25 seconds. This will get the starch and water molecules to break down the crystalline regions, producing soft, ready-to-eat bread.