The shell just made by Puffs is very brittle. Leave it overnight, because there is moisture in the air, and Puffs' shell is dry. If it absorbs the moisture in the air, it will become soft. Puffs can be eaten normally after softening, but the taste is not as crisp and delicious as when they were just made. Puffs can be stored in the refrigerator and put back in the oven if necessary.