What is the safest way to reheat leftovers?

Reheating leftovers in a microwave until hot is considered the safest option because microwaves heat food quickly and effectively, ensuring that it reaches a safe internal temperature in a relatively short period. This rapid heating minimizes the amount of time food spends in the temperature danger zone, which is between 40°F and 140°F. Bacteria can grow rapidly in this range, so it's crucial to quickly get food through this zone to safe temperatures of 165°F or higher.

Using a microwave also allows for even reheating when the food is stirred or rotated during the process, which helps to eliminate cold spots where bacteria might survive. It's advisable to use a food thermometer to ensure the leftovers reach the recommended temperature throughout to ensure safety.

Other methods might take longer or not evenly heat the food, potentially allowing harmful bacteria to survive. For instance, reheating at a low temperature for a long time or at a low temperature in the oven could prolong exposure to potentially unsafe temperatures. Similarly, reheating on the stovetop can lead to uneven heating unless carefully monitored, increasing the risk of cold spots.