Fresh loaves of bread from the bakery are both delicious and often free of the preservatives that come with buying sliced, bagged bread off the supermarket shelves. However, these same loaves of bread tend to become stale much more quickly when sliced. It’s quite the dilemma, especially for those who want to avoid throwing away and wasting stale bread (or are tired of turning said stale pieces into breadcrumbs or croutons).
The science behind staling involves the structure of starch, which is an essential part of bread. Starch, in its natural state, has a stiff crystalline structure. When this starch is introduced to water and heated (baked as a loaf of bread), the starch undergoes a process called gelatinization. In other words, the starch swells, stretches, and loses its stiff structure.
Image by Noel Haegens/Bread and the Technology of Bread Production
As soon as the bread starts to cool, however, the starch slowly starts to regroup into an organized crystalline structure again. This gradual return to structure is the primary reason for the tough, firm texture of stale bread.
Exposure to air speeds up this recrystallization process; therefore, the trick to keeping your bread from going stale for longer is to maximize the benefit of the crust as an air barrier.
These are my two best tips for avoiding yucky stale bread:
Don’t buy pre-sliced bread.
Pre-sliced bread has many more exposed surface areas, which allows air to work its way into the bread.
Slice into the center of your bread instead of starting at one of the ends.
Then, push the two cut sides together after removing your slices.
The two heels act as a barrier against the air, preventing air from having ready access to the crumb (which is much more susceptible to staling).
These pro-tips have allowed me to enjoy fresh bread for much longer than I initially thought I could, and I encourage you to try them. But if all else fails and your bread still becomes as hard as a rock, well… we have a pretty ingenious hack that will re-soften your loaf. (Don’t worry, we know other things go stale too: here are great ways to reuse your stale bagels, stale potato chips, and stale cereal as well).