Never before have so many blast furnaces been idled for a long period worldwide. Steel producers are under immense pressure to respond quickly to changing circumstances in order to remain competitive. The ability to restart and ramp-up production facilities, and blast furnaces in particular, is essential in this respect. This article discusses a method to restart idled blast furnaces in a controlled and safe way, making hot metal of usable quality available to the steel plant in the smoothest possible way. The method has been developed originally for the recovery of chilled blast furnace hearths but is also applicable for starting up after a long stop. The authors have investigated risks that may emerge during restarts and describe how these, in their experience, are mitigated.