Yes, MyMilk trays are designed to be endlessly reusable. Once Michelle, the creator of MyMilk, stopped pumping breast milk for her son, she started using MyMilk trays to freeze purees and soft foods in half-ounce portions as her son Benjamin transitioned to solids. Another alternative use for MyMilk trays is to freeze homemade minced garlic or ginger and homemade herbed butter cubes for the grown-ups in the household.