Fact

• Salt is hygroscopic, which means it absorbs moisture from the atmosphere. Sugar is another common hygroscopic ingredient.

Function

• If salted crackers are left exposed to air, the salt will absorb moisture. This causes the crackers to turn soft rather than hard.

Effects

• The same hygroscopic principle that turns crackers soft is also the reason why salt shakers will often clump up and become clogged when used in humid conditions.

Prevention

• To prevent crackers from going stale and turning soft, store them in airtight containers or bags. Any exposure to air will allow for moisture absorption.

Solution

• Slightly stale crackers -- those displaying softness and not mold -- can be salvaged with some crisping in a conventional oven or with short periods in the microwave. The heat dries out the excess moisture.