About to whip up a batch of your grandmother’s best recipe for chocolate chip cookies, go to scoop brown sugar only to have it bend your spoon? After being opened, brown sugar can turn hard as a rock making it unusable in recipes. This hardening happens when the sugar has been exposed to air, and the moisture in the molasses that coats it and keeps it smooth evaporates. There are two ways to avoid this dilemma, one is preventative, and one is repair.
To prevent your brown sugar from going hard, simply place one or two large marshmallows inside the bag/container with the brown sugar. The sugar will magically (or scientifically) absorb the moisture from the marshmallow, which keeps the sugar soft. If it’s too late and the brown sugar is already hardened, simply put the sugar in a microwave safe container, and cover in a damp paper towel and microwave at 20 second intervals until softened.