Abstract: A continuously controlled process for cooling a material to within a desired temperature range as the material moves along a path, especially suitable for situations in which the amount of material being cooled is unknown. The material is first contacted with a known amount of cooling liquid, e.g., water. The temperature of the water (or steam) is measured after contact with the material, and this information is then used to determine the amount of additional cooling required. An embodiment utilizing the process to cool calcined coke in a rotary cooler is described.