One of the critical factors in controlling pathogens in food is controlling temperature. Disease-causing microorganisms such as bacteria, viruses and parasites grow very slowly at low temperatures, multiply rapidly in mid-range temperatures and are killed at high temperatures. For safety, perishable foods must be held at proper cold temperatures to inhibit bacterial growth or cooked to temperatures high enough to kill harmful microorganisms. It is essential to use a food thermometer when cooking turkey products to prevent undercooking, and consequently, prevent foodborne illness. Many food handlers believe visible indicators, such as color changes, can be used to determine if foods are cooked to a point where pathogens are killed. However, recent research has shown that color and texture indicators are unreliable. Using a food thermometer is the only reliable way to ensure safety and to determine the "doneness" of turkey. Types of Thermometers Food thermometers come in several types and styles and vary in technology and price. Digital Food Thermometers Thermocouple: Of all food thermometers, the thermocouple reaches and displays the final temperature the fastest, within 2 to 5 seconds. The temperature is indicated on a digital display. Since the thermocouple responds so rapidly, the temperature can be quickly checked in a number of locations to ensure the turkey is thoroughly cooked. Thermocouples are not designed to remain in the food while it is cooking. They should be used near the end of the estimated cooking time to check for final cooking temperatures. To prevent overcooking, check the temperature before the turkey is expected to finish cooking. Thermocouples can be calibrated for accuracy. Thermistor: Can measure temperature in thin foods, as well as thick foods. Because the center of a turkey is usually cooler than the outer surface, the tip should be placed in the center of the thickest part of the turkey. Thermistors are not designed to remain in the turkey while it is cooking. They should be used near the end of the estimated cooking time to check for final cooking temperatures. To prevent overcooking, check the temperature before the turkey is expected to finish cooking. Not all thermistors can be calibrated. Check the manufacturer's instructions. Oven Cord Thermometers: Allows the cook to check the temperature of food in the oven without opening the oven door. A base unit with a digital screen is attached to a thermistor-type food thermometer probe by a long metal cord. The probe is inserted into the food and the cord extends from the oven to the base unit. The base can be placed on the counter. The thermometer is programmed for the desired temperature and beeps when it is reached. Oven cord thermometers cannot be calibrated. Dial Food Thermometers Oven-Safe: Designed to remain in the turkey while it is cooking in the oven. An oven-safe thermometer is convenient because it constantly shows the temperature of the turkey while it is cooking. Some models can be calibrated. Check the manufacturer's instructions. Instant Read: Quickly measures the temperature of food in about 15 to 20 seconds. It is not designed to remain in the turkey while it is cooking in the oven, but should be used near the end of the estimated cooking time to check for final cooking temperatures. To prevent overcooking, check the temperature before the turkey is expected to finish cooking. For accurate temperature measurement, the probe must be inserted the full length of the sensing area (usually 2 to 3 inches). Some models can be calibrated. Check the manufacturer's instructions. Single Use Thermometers Pop-Up Thermometers: Commonly found in whole body turkey and large breast cuts, but they also are available for purchase. These thermometers are reliable to within 1ºF to 2ºF, if accurately placed in the product. The "pop-up" temperature device indicates the turkey has reached the final temperature for safety and doneness. Most food experts suggest the temperature also be checked with a conventional thermometer in several places. General Guidelines Tips to use when measuring temperatures of various types of turkey, whole body, parts and products. Check oven thermostat and oven temperature to verify the oven setting. Recalibrate, if necessary. A 25ºF variation can make a 5 percent difference in the yield of cooked turkey. Be sure to sanitize the thermometer before and between each use. Wash it; then immerse the stem in 170ºF water for 30 seconds or wipe with a sanitizer. Check for accuracy The accuracy of an oven-safe or instant read thermometer can be verified and the thermometer calibrated, if necessary. To test the thermometer, insert at least 2 inches of the stem into boiling water. It should read 212ºF. Some thermometers have "test" marks on them at 212ºF. Also, some thermometers, especially the "instant-read" type, have a recalibration or adjustment nut under the dial. Turn the nut, if necessary, to adjust. Inserting the thermometer When measuring the temperature of the whole bird, follow these procedures: Insert thermometer in the deepest part of breast or thigh. The thermometer should reach 170ºF in the breast or 180ºF in the thigh. When inserting the thermometer in the breast, insert from the side. The thermometer is easier to read and more accurate than when inserted from the top. Be sure to insert a thermometer into each bird. To measure the temperature of turkey parts and products, follow the same procedure of inserting the thermometer in the deepest part of the piece. Internal Temperatures In the Cooking Methods sections that follow, you'll see tips with each set of cooking instructions that include suggested internal temperatures. These temperatures are somewhat higher than those recommended by the Food and Drug Administration (FDA). This is because the FDA's recommendations are for safety-temperatures sufficient to kill any bacteria that may be present. The National Turkey Federation recommends slightly higher internal temperatures in order to achieve optimum eating quality and to make carving and slicing easier.		Introduction Cooking Methods Boning a Whole Turkey Basics of Cooking Seasonal Versatility Measuring Temperature Cooking Whole Turkey Cooking Small Parts Turkey Stock Heating & Holding Return to Table of Contents