Temperature Control and the Danger Zone
What you must understand
The temperature danger zone is the range where bacteria multiply fastest, commonly 41°F to 135°F (5°C to 57°C). Keep food out of it or limit time in it to four cumulative hours.
Know the key temperatures. Cold holding is 41°F or below. Hot holding is 135°F or above. Refrigerators should run at 38°F to 41°F, and freezers at 0°F or below. Cook poultry to 165°F, ground meat to 155°F, and whole fish and pork to 145°F. Reheat leftovers to 165°F for 15 seconds within two hours. Cool cooked food from 135°F to 70°F within two hours, then to 41°F within four more hours, for a total of six hours.
Use a calibrated probe thermometer to check internal temperatures, and measure the thickest part or the center of the food. Sanitize the probe between uses. Keep a temperature log. When thawing, use refrigeration, running water at 70°F or below, a microwave followed immediately by cooking, or cook from frozen; never thaw on the counter.
Traps to watch
Questions often confuse cumulative time with a single stretch; four hours adds up across the day. Do not confuse the danger zone limit (4 hours) with the cooling limit (6 hours total). Do not accept the outside of a food as a temperature reading. Do not use hot holding to reheat; reheat on a stove or microwave to 165°F, then hold at 135°F.
Rule of thumb
When a question gives a temperature and asks if it is safe, compare it to the nearest boundary: below 41°F is cold-safe, above 135°F is hot-safe, and anything between is danger-zone time. If food has been in the zone for more than four hours, discard it.