There are also brown sugar keepers that are created for this very reason, like this container that our contributor Sally swears by. The airtight lid keeps air out while a terracotta disk soaked in ...

The ProKeeper + by Progressive Brown Sugar ProKeeper storage container combines high quality ... To keep sugar from drying out, soak the removable terra cotta disk in water & snap it under the ...

A couple of marshmallows or a dampened terracotta disk placed in the airtight container with the sugar work, too, Lahud says, but the process is slow, so give it a few days to soften. To rescue ...