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Thurston County Extension
Food Safety: Cooking Equipment
Take Advantage of Accurate Thermometer
The Olympian, August 19, 1998
Thermometers are accurate only when they are used according to manufacturer's instructions. The instructions should tell you how far the thermometer must be inserted in a food to give an appropriate reading.
Additionally, the instructions should guide you through calibrating the thermometer to ensure that the temperature you read on the dial is accurate. While these steps may sound like lots of work, they are quick and easily become habits that help you serve safe food to your family and friends.
QUESTION: I've lost the directions fro the thermometer. What should I do?
ANSWER: If you don't have instructions, take a close look at the metal stem of your thermometer. Most metal stem thermometers have some kind of marking or indentation on the stem. Generally, that shows one end of the sensing device that measures temperature. When you use the thermometer, it should be inserted into the food up to this mark. Usually, metal stem, dial type thermometers need to be inserted 2 to 3 inches into the food.
Be sure to measure the temperature in the geometric center or thickest part of the food. And, after you insert the thermometer, wait until the needle on the temperature dial stops moving and is stable for bout 15 seconds.
You should also look carefully at the dial cover. Plastic covers are used on instant-read metal stemmed thermometers. They should never be used in foods during cooking in an oven, on a stove, or in a microwave oven. The plastic will melt. They are designed to spot-check food temperatures and not to be left in foods during cooking.
QUESTION: Where should I place the thermometer in different kinds of foods?
ANSWER: When you take the temperature of beef, port or lamb roasts, the thermometer should be placed midway in the roast, avoiding touching any bone. If the roast has an irregular shape, check the internal temperature in several places. If you have an instant-read thermometer, wait for 15-20 seconds to get an accurate reading.
With an over-safe thermometer, you'll need to wait 1-2 minutes for an accurate measurement. If you're cooking hamburgers, chops or steaks, you should insert an instant-read thermometer from the side toward the center, so the metal stem is inserted fully into the food for an accurate ding.
Poultry: When cooking whole poultry, the thermometer should be inserted into the thickest part of the thigh. If the poultry is stuffed, the thermometer needs to be placed in the center of the stuffing. Additionally, because of the irregular shape, it's a good idea to check the temperature in a number of places.
Combination dishes and casseroles: Insert the thermometer into the thickest portion of the food and avoid touching the dish or pan. Make sure it is inserted 2-3 inches and check the temperature in several places or after stirring.
QUESTION: What is calibration?
ANSWER: Calibrating your thermometer is a way of testing your thermometer for accuracy to make sure that the temperature you read is correct. If you drop a thermometer, expose it to extreme temperatures or with use over time, it may need to be adjusted to be accurate. The easiest way to calibrate your kitchen thermometer is to insert it into a small container of partially melted ice. Wait until the need indicator stabilizes. The temperature should read 32 degress F. If it doesn't, most thermometers have some sort of adjustment capacity. Ready your directions.
B. Susie Craig
Area Faculty
WSU Cooperative Extension Thurston County
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WSU Extension programs and employment are available to all without discrimination. Evidence of noncompliance may be reported through your local Extension Office. Cooperating agencies: Washington State University, U.S. Department of Agriculture, and the county of Thurston.
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