Using Brown Sugars

Brown sugar is soft and clingy because its molasses film— whose glucose and fructose are more hygroscopic than sucrose—contains a significant amount of water. Of course, if brown sugar is left exposed to dry air, it will lose its moisture through evaporation and become hard and lumpy. It can be kept moist by storing it in an airtight container, and resoftened by closing it up with a damp towel or piece of apple from which it can absorb moisture. Because brown sugar tends to trap air pockets between groups of adhering crystals, it should be packed down before its volume is measured.