When does cupcake icing go off?

Cupcake icing can typically last for about one to two weeks when stored properly in the refrigerator. If the icing contains dairy or perishable ingredients, it may spoil more quickly, so it's best to consume it within a week. Always check for signs of spoilage, such as an off smell, discoloration, or mold. For longer storage, consider freezing the icing, which can extend its shelf life to several months.