Time & Temperature Control
THE TDZ
Foodborne pathogens, the unfriendly microorganisms that cause illness, grow rapidly between 41ºF and 135ºF. (If you prefer the Celsius scale, it’s 5ºC to 57ºC.) The range between 41º and 135º is referred to as the “TDZ… Temperature Danger Zone.” When food is held in the TDZ we say it is “temperature abused.”
“TCS” foods, those that require “Time and Temperature Control for Safety,” must be kept out of the TDZ. We frequently temperature abuse our food intentionally. For example, when we bring whole chickens out of the walk-in cooler into the kitchen for butchering, we are temperature abusing the chicken. It is best to limit the quantity we are working with at any one time to reduce the time in the TDZ.
COLD FOOD COLD
For cold holding, TCS foods must be stored at 41ºF or lower. This requirement applies everywhere… in the walk-in cooler, in the tall reach-ins on the line, in the undercounter refrigerators, and of course, on a buffet or salad bar. If you have an expeditor, cold condiments that will be added to plates as they come off the line must also be kept below 41ºF.
HOT FOOD HOT
In hot holding – steam table, chafing dishes with Sterno, hot food on a buffet – food must be held at 135ºF or higher. (Keep in mind that this temperature is for safety, and not necessarily a proper serving temperature. Clam chowder being held at 135ºF is safe, but not hot enough for service.)
TAKING TEMPERATURE LOGS
Scheduled temperature-taking is critical to time & temperature control. Refrigeration or heating equipment can fail without notice, jeopardizing the safety of your food and your investment in it. You should work a consistent schedule of taking temperature logs into your routine.
Plan to take temperatures throughout the operation at least every four hours. Ideally, taking temperatures at two-hour intervals allows for corrective action. After four hours, food that is in the TDZ, Temperature Danger Zone, must be discarded. At two hours, you need only correct the temperature of cold TCS food in another refrigerator. The time that the food was above 41ºF should not exceed four hours. Remember, however, hot food that is being reheated for hot holding must be quickly reheated to 165ºF, then returned to hot holding at 135ºF or higher.