Time and Temperature Control

Almost every time and temperature rule in food safety is a way of limiting how long food sits in one range.

• The temperature danger zone is 41°F to 135°F (5°C to 57°C) — the range where bacteria multiply fastest.
• The zone between 70°F and 125°F is the most dangerous of all; move food through it as quickly as possible.
• Discard any TCS food held in the danger zone for more than 4 hours in total (cumulative, across the whole day).
• Cold does not kill bacteria — refrigeration and freezing only slow or pause growth. When food warms up, growth resumes.
• Minimize the time food spends out during prep: work in small batches and keep the rest refrigerated.

You cannot judge temperature by sight, smell or touch. A calibrated thermometer is the only proof food is safe.

• A bimetallic stemmed thermometer must be inserted to the dimple mark and is read after the needle stabilizes; a thermocouple/thermistor reads from the tip and is faster and more accurate.
• Infrared (laser) thermometers measure surface temperature only — useful for quick checks on deliveries, never for internal cooking temperatures.
• Always take the reading in the thickest part or center of the food, away from bone, fat and the pan; check more than one spot.
• Clean and sanitize the probe before and after every use to avoid turning your thermometer into a contamination tool.
• Calibrate using the ice-point method (ice water = 32°F) or the boiling-point method (212°F at sea level), and recalibrate after a drop or a big temperature change.

Cooking is the main 'kill step' in the flow of food. Each temperature must be held for a specific time to be effective.

• Cook poultry (whole and ground), stuffing, stuffed meats and any reheated TCS food to a minimum internal temperature of 165°F for 1 second.
• Cook ground meats (beef, pork), injected meats, and ground/mechanically tenderized products to 155°F for 17 seconds.
• Cook whole cuts of beef, pork, veal, lamb, fish and shell eggs cooked for immediate service to 145°F for 15 seconds.
• Roasts may be cooked to 130°F for 112 minutes or another approved time-temperature combination.
• Cook fruit, vegetables, grains and legumes that will be hot-held to 135°F.
• Food cooked in a microwave must reach 165°F, be stirred or rotated partway through, be covered, and then stand for 2 minutes before serving.

Holding equipment keeps food out of the danger zone — it is not designed to heat food up or cool it down.

• Hold hot food at 135°F or above, and cold food at 41°F or below.
• Check holding temperatures at least every 4 hours, and ideally every 2 hours so there is time to correct a problem before food must be discarded.
• Never use hot-holding equipment to reheat food — reheat on a stove, in an oven or in a microwave first, then transfer.
• Stir food in hot-holding units to distribute heat evenly, and keep containers covered to hold temperature and block contamination.
• Time as a public health control (holding without temperature control) is allowed only with a written policy: label the food with the discard time and discard it after 4 hours (hot or cold) or 6 hours for cold food that starts at 41°F and never exceeds 70°F.

Improper cooling is one of the most frequently cited causes of foodborne illness outbreaks — a large hot pot in a walk-in can stay in the danger zone for many hours.

• Cool cooked food from 135°F to 70°F within 2 hours, then from 70°F to 41°F within 4 more hours (6 hours total).
• If food has not reached 70°F within the first 2 hours, you must reheat it to 165°F and start cooling again, or discard it.
• Speed cooling by using shallow pans (2 inches or less), dividing food into smaller portions, using an ice-water bath, adding ice paddles or ice as an ingredient, or using a blast chiller.
• Leave containers loosely covered or uncovered while cooling in the walk-in (protected from overhead contamination) so heat can escape.
• Reheat previously cooked TCS food to 165°F within 2 hours before hot-holding it. Commercially processed, ready-to-eat food being hot-held need only reach 135°F.

Thawing on the counter is one of the most common violations: the outside of the food sits in the danger zone for hours while the center is still frozen.

• In a refrigerator at 41°F or below — the safest method, but it requires planning ahead.
• Under cold running water at 70°F or below, in a clean prep sink, with enough flow to wash loose particles into the overflow — for no more than 2 hours.
• In a microwave, only if the food will be cooked immediately afterward.
• As part of the cooking process, going straight from frozen to cooked (common with frozen patties and vegetables).
• Never thaw food at room temperature, in standing warm water, or by leaving it out overnight.