No need to use old baguettes and other stale bread just for croutons. Bread stales due to a process called retrogradation, but it can be returned to a softened state.
For a bread lover, few things are more pleasurable than tearing into the plush crumb of a crusty baguette—or more disappointing if you’ve waited too long and the loaf has gone stale.
But all is not lost. Hard bread can actually be brought back to life with one simple trick.
Run it under cold water.
The staling of bread and other starch-based foods is due to a process called retrogradation.
In the bread-making process, water hydrates the starches in the flour and then, as the loaf bakes, the starches gelatinize and soften. Over time, the starches in that baked loaf crystallize and incorporate water into the crystalline structure, leading to an apparently dry, stale loaf.
The good news is that the water doesn’t travel very far: Most of it remains trapped within the starch crystals, and this makes the retrogradation process reversible—at least for a little while.
With heat, the starches will reabsorb the moisture and soften again, so toasting slices of bread is one way to revive a loaf. The reabsorbed moisture on the surface will evaporate but the interior returns to a more plush state. But what if you want to reverse the staling of an entire loaf and enjoy bread that’s softened through and through?
That requires a more gentle touch because in order to avoid water loss due to evaporation, you need to gradually heat the entire loaf to the gelation point (about 140 degrees)—but without heating it to the boiling point of water (212 degrees).
In addition, with crusty breads such as baguettes and boules, you also need to supply water to the exterior of the loaf to ensure that all the starches can properly soften.
It is important to note that because reheating a stale loaf doesn’t free the starches to move around the way that it does in a just-baked loaf, they recrystallize much more quickly. This fix only lasts for only a few hours or so, so make sure to serve or use your revived bread immediately.