Temperature Control and Danger Zone Flashcards

During a power outage, a refrigerator has been off for 3 hours. The internal temperature reads 10°C. What should be done with the potentially hazardous foods inside?

Answer: Evaluate each item: discard PHFs that have been above 4°C for more than 2 hours; items above 4°C for less than 2 hours can be kept if quickly cooled

At 10°C for 3 hours, PHFs have been in the danger zone beyond the 2-hour safe limit. Foods that were above 4°C for more than 2 hours must be discarded. Non-PHFs like condiments may be safe to keep.

What type of thermometer is most appropriate for checking thin foods like hamburger patties?

Answer: A thermocouple or thin-tip digital probe thermometer

Thin-tip digital probe thermometers or thermocouples can be inserted into thin foods to get an accurate internal reading. Infrared thermometers only measure surface temperature, and oven thermometers measure air temperature.

What is the proper sequence for cooling a large pot of soup safely?

Answer: Transfer to smaller shallow containers, place in an ice bath, stir frequently, then refrigerate once cooled to 20°C or below

Large volumes of hot food cool too slowly in a refrigerator and can raise the fridge temperature. Dividing into shallow containers increases surface area, ice baths and stirring accelerate heat removal, and refrigerating at 20°C or below completes safe cooling.

An infrared (laser) thermometer is best used for:

Answer: Quickly scanning surface temperatures of equipment, holding units, and delivery vehicles

Infrared thermometers measure surface temperatures only and are ideal for quick equipment checks, receiving inspections, and monitoring holding unit temperatures. They cannot measure internal food temperatures and should not replace probe thermometers.

Why must food thermometer probes be sanitized between uses?

Answer: To prevent cross-contamination between different foods, especially between raw and ready-to-eat items

Thermometer probes can transfer pathogens from one food to another. Sanitizing between uses prevents cross-contamination, particularly critical when checking raw meats and then ready-to-eat foods.

Food that has been properly cooled and stored can be reheated how many times safely?

Answer: Only once — food should be reheated only once to 74°C; leftovers from reheated food should be discarded

Food should only be reheated once. Each cooling and reheating cycle provides additional opportunity for bacterial growth and toxin formation. After one reheat cycle, any uneaten portions should be discarded.