Sugar crystals become sticky in a monsoon pantry due to the high humidity, which causes the sugar to absorb moisture from the air and dissolve slightly, creating a sticky surface.
Sugar is hygroscopic, meaning it readily absorbs moisture from its surroundings. During the monsoon season, humidity levels are significantly elevated. This increased moisture in the air comes into contact with the sugar crystals. The sugar crystals then absorb this moisture. As the sugar absorbs moisture, the outer layers of the crystals begin to dissolve, forming a thin layer of sugary syrup. This syrup is what causes the sugar to clump together and feel sticky. The higher the humidity, the more moisture the sugar absorbs, and the stickier it becomes. This is why properly storing sugar in an airtight container is crucial, especially in humid climates.
To prevent sugar from becoming sticky, store it in an airtight container with a few grains of uncooked rice. The rice will absorb excess moisture, helping to keep the sugar dry and free-flowing.