Why do hard/crunchy foods soften when you leave them out and soft foods (left in the same conditions) harden?



If I leave the bread out on the counter (no package of any kind) , it will start getting hard .If I leave out chips , they will start to soften (they lose the crunchiness) and that happens with other foods as well.Like cakes , pastries, bagels vs pretzels, and any other crunchy snack.

Wouldn’t it make sense that the same conditions would bring them to the same (or at least, similar) states?

In: Chemistry

Crunchy food are low in water content, which means it will absorb moisture from the relatively wetter air.

The reverse for soft and wet food which will dry out and get hard because it will evaporate its moisture to the relatively drier air

It’s basically to do with moisture content. Soft fresh bread contains water, which evaporates when left out leaving the bread dry and crunchy.

Chips on the other hand are very dry, but will absorb moisture when left out, which then makes them soggy

The water in soft foods will evaporate because the air is more dry, so as the water particles move to the air the food starts to dry up and get crunchy. The opposite happens with really dry foods: the food is more dry than the air and gradually sucks water particles out of the air.