Sqwincher Qwik Stiks are a powdered product, powders are hygroscopic, meaning they attract and hold water molecules, which when absorbed can make the powder go hard. We recommend they be stored in a cool, dry environment, out of sunlight as they can sweat inside the packet. If stored outside of these conditions the powder may go hard, if this happens they are still fine to use they just need to be squeezed and broken up inside the sachets before being mixed in with water.