How long should leftovers be cooled before refrigeration?

The correct guideline for cooling leftovers before refrigeration is that they should be cooled within 2 hours. This is crucial for food safety, as allowing leftovers to sit at room temperature for too long can promote the growth of harmful bacteria. The 2-hour rule is a standard recommendation supported by food safety organizations to help prevent foodborne illnesses.

When food is left out in the "danger zone" (between 40°F and 140°F) for more than 2 hours, it becomes unsafe to eat. The longer food remains in this temperature range, the higher the risk of bacterial growth. Therefore, cooling leftovers to a safe temperature and promptly refrigerating them within the specified timeframe is essential to maintaining food safety and integrity.