You can't. According to query 39, health. Com, the rock candy Sydney has been cooked, and it is easy to breed bacteria if it is left for too long, and the nutrition of rock candy Sydney will also decrease after overnight. Therefore, it is not allowed to eat rock candy Sydney overnight, so as not to cause abdominal pain, diarrhea, stomach pain and other adverse reactions. The main ingredients of rock candy Sydney are rock candy and Sydney. It has the functions of relieving cough, resolving phlegm, moistening lung and clearing dryness. It has a certain auxiliary treatment effect on cough, expectoration and sore throat of patients with upper respiratory tract infection and tracheitis.