What must be done to the oil in the fryer before cleaning?

Allowing the oil in the fryer to cool down before cleaning is critical for safety and effectiveness. Hot oil can cause severe burns and is hazardous to handle, making it essential to wait until the oil reaches a safe temperature. This precaution not only protects the individual cleaning the fryer but also ensures that any cleaning agents used will not interact with hot oil, which can be dangerous or ineffective.

Cooling the oil also makes it easier to handle when it comes time to drain or filter it, as warm oil can still be viscous and difficult to manage. This approach aligns with standard operating procedures in food service environments where safety and efficiency are priorities.

The other options—draining the oil completely, filtering the oil, and replacing it with fresh oil—are all important steps in managing fryer maintenance but cannot be initiated until the oil has cooled down. Therefore, the prerequisite of allowing the oil to cool is key in the cleaning process.