It's frustrating to find that your brown sugar is hard as a rock just when you've decided to bake chocolate chip cookies or an apple crisp. Hacking away at what used to be the soft texture of brown sugar, you'll leave bits of sugar everywhere in your kitchen and risk injury from a slipping knife or spoon. Plastic resealable bags for brown sugar have gone a long way in helping to alleviate the problem, but if your sugar does harden, it's good to know that the "apple trick" is foolproof.
Wash an apple of any variety under running water. Fresh fruit can harbor harmful bacteria from the soil or water where it was grown or it may get contaminated during processing or storage, so thorough washing is essential.
Cut the apple into wedges about 1 inch thick. You'll only need one wedge to soften the sugar, so plan to eat the rest of the apple for lunch or an afternoon snack.
Place one apple wedge into each 1 lb. bag of brown sugar and place the sugar in a tightly sealed plastic bag if it's not already stored in plastic. If the current plastic bag doesn't seal tightly, wrap the top with a rubber band to secure the seal.
Keep the apple wedge in the brown sugar for one to two days. At that point, the sugar will have softened enough to use and you can discard the apple.