Which of the following is not an effective rapid cooling technique?

Placing food on the counter overnight is not an effective rapid cooling technique because it allows food to remain in the temperature danger zone (between 40°F and 140°F), where harmful bacteria can grow rapidly. Rapid cooling techniques are designed to bring food down to a safe temperature quickly to minimize the risk of foodborne illness.

Using an ice water bath, placing food in a freezer, and using shallow pans are effective methods. An ice water bath cools food quickly by surrounding it with ice, which accelerates heat transfer. Placing food in a freezer can rapidly lower its temperature, though it should be monitored to prevent it from freezing solid. Shallow pans increase the surface area of the food, allowing it to cool more evenly and quickly. Therefore, only leaving food out at room temperature overnight fails to meet the safety standards for proper cooling.