Boiled milk frosting does not form a crust. If you need to set the frosting, using the refrigerator is the way to go. The frosting will get soft again once it is at room temperature. If you need a frosting that crusts, try u003ca href=u0022https://cookingwithcarlee.com/crusting-buttercream/u0022 data-type=u0022postu0022 data-id=u00228603u0022u003ecrusting buttercreamu003c/au003e.