Staling

Staling, or "going stale", is a chemical and physical process in bread and other foods that reduces their palatability. Stale bread is dry and leathery.

Contents

[hide]

Mechanism and effects

Staling is not, as is commonly believed, simply a drying-out process due to evaporation. Bread will stale even in a moist environment, and stales most rapidly at temperatures just above freezing. (McGee 2004, p. 310) Bread stored in the refrigerator will have increased staling rates and should therefore be kept at room temperature. However, refrigeration delays the growth of mold and extends the shelf life of bread.

Although the precise mechanism of staling is still unknown, one important mechanism appears to be migration of moisture from the starch granules into the interstitial spaces, degelatinizing the starch. The starch amylose and amylopectine molecules realign themselves causing recrystalisation. This results in stale bread's leathery, hard texture.

Additionally, pleasant "fresh" flavor is lost to the air, and often unpleasant flavor is absorbed from it as well, especially in a confined space with other food such as a refrigerator.

Countermeasures

Anti-staling agents used in bread are fatty acids as monoglyceride and diglyceride and wheat gluten.

Culinary uses

Specifically stale bread is an important ingredient in many dishes, some of which were invented for the express purpose of using up otherwise unpalatable stale bread. Examples include bread pudding, bread sauce, skordalia, garbure, fondue, croutons, haslet, gazpacho, wodzionka, french toast, bread dumplings and flummadiddle.

In medieval cuisine, slices of stale bread, called trenchers, were used instead of plates.

Destaling

Stale bread can be partially destaled by heating to 60 °C (140 °F) in a conventional oven or microwave oven. This re-gelatinizes the starch granules. However if not eaten before it cools or dries, the bread is even worse than before due to the moisture loss.

References

Further reading