Final answer:
The first step in cooling a stockpot of soup should be to use an ice bath, which helps rapidly reduce the soup's temperature and pass through the danger zone where bacteria multiply quickly.
Step-by-step explanation:
When cooling a stockpot of soup, the first step should be to use an ice bath to rapidly lower the soup's temperature. This method is crucial for food safety, as it helps quickly pass through the temperature range (between 140°F to 40°F) where bacteria can rapidly multiply. Submerging the hot soup container in an ice bath facilitates this by increasing the conductive and convective heat loss from the soup to the surrounding cold water and ice mixture. It is efficient because the large surface area of the container is exposed to the cold temperature, and the thermal conductivity of water is higher than air, allowing for faster heat transfer.
Specifically, the correct procedures would be to fill a sink or large container with ice and cold water and then submerge the stockpot into this bath. Stirring the soup occasionally can also help more evenly distribute the cooler temperature throughout. Moreover, using containers with larger surface areas would facilitate faster cooling because of the increased area for heat exchange. However, it's important to not seal the container tightly as the expansion of gases or steam needs to be accounted for during cooling.