• When taking the temperature of beef, pork or lamb roasts, the food thermometer should be placed midway in the roast in the thickest part, avoiding the bone, fat and gristle. 
• When cooking, beef, pork, veal or lamb steaks or chops, insert the food thermometer in the thickest part, away from bone, fat or gristle. 
• When cooking hamburger patties or other thin pieces of beef, pork, veal or lamb, insert the food thermometer through the side. Make sure the food thermometer reaches the center.

• When cooking whole poultry, check the internal temperature in three places: the innermost part of the thigh, the innermost part of the wing and the thickest part of the breast. Avoid the bone.
  • For optimum safety, do not stuff whole poultry. If stuffing whole poultry, the center of the stuffing must reach a safe minimum internal temperature of 165 degrees F. 
• When cooking poultry parts (such as breasts, thighs and wings), insert food thermometer into the thickest area, avoiding the bone. 
• For thinner pieces of poultry, insert the food thermometer through the side. Make sure the food thermometer reaches the center.

• When measuring the temperature of a thin food, such as a hamburger patty, sausage, pork chop or thin chicken breast, the probe must be inserted in the side of the food so the entire sensing area (usually 2-3 inches for an “instant-read” food thermometer) reaches the center of the food.
• To avoid burning fingers, it may be helpful to remove the food from the heat source (if cooking on a grill or in a frying pan) and insert the food thermometer sideways after placing the item on a clean spatula or plate.

• Place the food thermometer into the thickest portion of the food or the center of the dish.
• Egg dishes should be checked in several places. To be sure these dishes are done, check to see that a thermometer at the center of the dish shows 160 degrees F. Also, use a thermometer to help guard against uneven cooking due to hot spots and inadequate cooking due to varying oven temperatures.

• Place the food thermometer into the thickest portion of the food or the center of the fish. 

To use the ice water method, fill a large glass with ice cubes. Add drinking water to the glass and stir well. Immerse the food thermometer stem a minimum of 2 inches into the mixture, touching neither the sides nor the bottom of the glass. Wait a minimum of 30 seconds and check the reading without removing the stem from the water. It should read 32 degrees F; if it does, the thermometer is calibrated. If not, adjust according to manufacturer instructions (some thermometers have a calibration nut or dial you can adjust).
 

To calibrate a food thermometer using the boiling water method, bring a pot of clean water to a boil. Place the stem of the food thermometer into the boiling water at least 2 inches deep, making sure it doesn't touch the sides or bottom of the pot, and wait a minimum of 30 seconds. Without removing the stem from the pan, wait for the reading to stabilize. The thermometer should read 212 degrees F at sea level. If the calibration is off, adjust according to manufacturer instructions (some thermometers have a calibration nut or dial you can adjust). If the thermometer doesn’t allow manual calibration, you may need to replace it.

For true accuracy, distilled water must be used. Boiling water’s temperature may vary in high altitudes. Most likely, the water would boil lower by at least 2 degrees F and perhaps lower by as much as 5 degrees F. Remember that water boils at a lower temperature in a high-altitude area. Check with the local Cooperative Extension System office or health department for the exact temperature of boiling water in your high-altitude area.

This food thermometer 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 or attached to the stovetop or oven door by a magnet. The thermometer is programmed for the desired temperature and beeps when it is reached. While designed for use in ovens, these thermometers can also be used to check foods cooking on the stove. Oven cord thermometers cannot be calibrated.
 

This utensil combines a cooking fork with a food thermometer. A temperature-sensing device is embedded in one of the tines of the fork. There are several brands and styles of thermometer forks on the market, using thermocouples and some using thermistors. The food temperature is indicated on a digital display or by indicator lights on the handle within 2 to 10 seconds (depending on the type). These lights will tell if the food has reached rare, medium, well done, etc. Particularly useful for grilling, the thermometer fork will accurately measure the internal temperature of even the thinnest foods. The thermometer fork should be used to check the temperature of a food towards the end of the estimated cooking time. Thermometer forks are not designed to remain in food while in the oven or on the grill. Thermometer forks cannot be calibrated.
 

Unlike traditional food thermometers, wireless and smart thermometers use a probe to measure the internal temperature of food and display the internal temperature on a base unit or smart device that is connected via Bluetooth or Wi-Fi. The thermometer probe remains in the food while cooking, and cooks can check the connected device for live updates. Depending on the device, the user can also receive notifications and status updates of the cooking process. Using a wireless or smart thermometer allows cooks to focus on other dishes without having to constantly check if their meat has reached a safe internal temperature. These thermometer probes can be used in a variety of cooking methods, including the oven, grill, and slow cooker. Smart thermometers can be calibrated.
 

These thermometers contain a coil in the probe made of two different metals that are bonded together. The two metals have different rates of expansion. The coil, which is connected to the temperature indicator, expands when heated. This food thermometer senses temperature from its tip and up the stem for 2 to 2 1/2 inches. The resulting temperature is an average of the temperatures along the sensing area. These food thermometers have a dial display and are available as “oven-safe” and “instant-read.”
 

This food thermometer is designed to remain in the food while it is cooking in the oven and is generally used for large items such as a roast or turkey. This food thermometer is convenient because it constantly shows the temperature of the food while it is cooking. However, if not left in the food while cooking, they can take as long as 1 to 2 minutes to register the correct temperature.

The bimetal food thermometer can accurately measure the temperature of relatively thick foods (such as beef roasts) or deep foods (foods in a stockpot). Because the temperature-sensing coil on the stem is between 2 to 2 1/2 inches long and the stem is relatively thick, it is not appropriate to measure the temperature of any food less than 3 inches thick.

There is concern that because heat conducts along the stem’s metal surface faster than through the food, the area of the food in contact with the thermometer tip will be hotter than the area a short distance to the side. To remedy this, the temperature should be taken in a second, and even a third, area to verify the temperature of the food. Each time the thermometer is inserted into the food, let the thermometer equilibrate (come to temperature) at least 1 minute before reading the temperature.

Some models can be calibrated. Check the manufacturer’s instructions.
 

This food thermometer quickly measures the temperature of a food in about 15 to 20 seconds. It is not designed to remain in the food 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 food is expected to finish cooking.

For accurate temperature measurement, the probe of the bimetal coil thermometer must be inserted the full length of the sensing area (usually 2 to 3 inches). If measuring the temperature of a thin food, such as a hamburger patty or boneless chicken breast, the probe should be inserted through the side of the food so that the entire sensing area is positioned through the center of the food. Some models can be calibrated. Check the manufacturer’s instructions.
 

One of the most recent developments in the retail food market is the emergence of disposable temperature indicators. Several brands are available, and all make quick work of determining if a food has reached its final temperature. These temperature sensors are designed for specific temperature ranges, for example, 160-170 degrees F. It is important that the sensors be used only with foods for which they are intended. Read the package directions to ensure that the temperature the sensor will reach is consistent with the safe temperatures listed above.

The sensors are made from special temperature-sensitive materials and inserted into food. When the food reaches a safe temperature, the sensor changes color. They are designed to be used only once. However, if the desired temperature has not been reached, they can be reinserted until the temperature is reached. These sensors cannot be left in a food while it is cooking. They should be used near the end of the estimated cooking time. To prevent overcooking, check the temperature before the food is expected to finish cooking.

Disposable temperature indicators are made from materials approved by the U.S. Food and Drug Administration for contact with food.
 

Commonly used in turkeys and roasting chickens since 1965, the “pop-up” style disposable cooking device is constructed from a food grade nylon. The inside contains a stainless-steel spring and organic firing material. The organic firing material is specifically designed to dissolve at specific predetermined temperatures. Once the firing material dissolves, the stainless-steel spring releases the stem, allowing it to “pop up.” This indicates that the food has reached the correct final temperature for safety and doneness. Pop-up style disposable cooking devices are reliable to within 1 to 2 degrees F. However, proper placement is important. Checking with a conventional food thermometer is always recommended as an added precaution to properly gauging both safety and doneness.
 

Also called “spirit-filled" or “liquid in glass” thermometers, these thermometers are the oldest kind of food thermometer used in home kitchens. They have either metal or glass stems. As the internal temperature of the food increases, the colored liquid inside the stem expands and rises to indicate the temperature on a scale. Heat conduction in the metal stems can cause false high readings. They are designed to remain in the food while it is cooking. They should be inserted at least 2 inches deep in the thickest part of the food and are, therefore, not appropriate for thin foods. Some liquid-filled thermometers can be calibrated by carefully moving the glass stem within the holder.
 

These thermometers will measure temperatures ranging from 100 to 400 degrees F. They are used to measure the extra-high temperatures required for candy and jelly making, as well as frying with hot oil.
 

Of all food thermometers, thermocouple thermometers reach and display the final temperature the fastest — within 2 to 5 seconds. The temperature is indicated on a digital display.

A thermocouple measures temperature at the junction of two fine wires located at the tip of the probe. Thermocouples used in scientific laboratories have very thin probes, while others may have a thickness of 1/16 of an inch.

Since thermocouple thermometers respond so rapidly, the temperature can be quickly checked in several locations to ensure the food is safely cooked. This is especially useful for cooking large foods, such as roasts or turkeys, when checking the temperature in more than one place is advised. The thin probe of the thermocouple also enables it to accurately read the temperature of thin foods such as hamburger patties, pork chops and chicken breasts.

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 food is expected to finish cooking.

Thermocouples can be calibrated for accuracy.

Thermistor-style food thermometers use a resistor (a ceramic semiconductor bonded in the tip with temperature-sensitive epoxy) to measure temperature. The thickness of the probe is approximately 1/8 of an inch, and it takes roughly 10 seconds to register the temperature on the digital display. Since the semiconductor is in the tip, thermistors can measure temperature in thin foods as well as thick foods. Because the center of food is usually cooler than the outer surface, place the tip of the thermistor in the center of the thickest part of the food.

Thermistors 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 food is expected to finish cooking.

Not all thermistors can be calibrated. Check the manufacturer’s instructions.