Which method is effective for cooling foods quickly to prevent bacterial growth?

Cooling foods quickly is essential for preventing bacterial growth, and submerging food in ice water is one of the most effective methods for doing so. This technique allows the heat from the food to be rapidly transferred to the ice water, which is at a much lower temperature. The high thermal conductivity of water ensures that the food cools down uniformly and swiftly, reducing the time it spends in the temperature danger zone (40°F to 140°F), where bacteria can multiply rapidly.

Using this method, food can be brought down to safe temperatures much faster than by relying on air cooling or other methods that may leave the food at unsafe temperatures for longer periods. This practice is particularly useful for large batches of food, as it quickly lowers the temperature throughout the entire mass.

The other methods listed do not effectively lower the temperature of food as quickly. Leaving food at room temperature can allow bacteria to multiply, while sealing food in tightly sealed containers can trap heat and moisture, preventing efficient cooling. Placing food in a warm oven is counterproductive, as it would raise the temperature rather than lower it.