Sugar Gone Rock Hard? Can't use it? Well, here's how to soften hardened brown sugar so that it is usable again. Place a damp kitchen paper towel over the bowl of hard brown sugar. 30– 35 seconds (depending on your microwave) and you will need to push a fork or spoon through it. Use it as if does go back hard again after a day. #LearnToCook #CookWithCuriosity #TheCuriousFoodie #CookWithCatherine #CatherineFulvio #BallyknockenCookerySchool #CookerySchoolWicklow #CookingSchoolIreland #CookingTipsAn