It can be irritating when bread goes staleand chips lose their crunch if you leave them out too long. But instead of throwing them away, you can revive them to their former freshness in a matter of minutes.
The video above by the American Chemical Society’s Reactions team explains the chemistry behind the staling process. And as you may have guessed, it has a lot – but not all – to do with moisture.
The starch in bread, for instance, is made up of two molecules: amylose and amylopectin. After baking bread, the tessellating structures of amylopectin traps moisture. But that structure breaks down slowly over time, releasing the moisture and hardening the bread.
When chips are fried, on the other hand, they lose all their moisture, making them likely to re-absorb moisture from the air.
So how do we fix it?
It’s as easy as throwing your sad, soft chips in the microwave for 30 seconds to expel the moisture and reheating stale bread in the oven at 60 °C to suck it up again.