UNIVERSITY PARK, Pa. -- While most cooks believe they can tell when meat is done by the color or by giving it a little squeeze, looks can be deceiving. The only accurate and safe way to ensure doneness is to use a meat thermometer, according to a meat scientist in Penn State's College of Agricultural Sciences.

"A hamburger that looks done may not be safe to eat," says Edward Mills, associate professor of dairy and animal science. "Foods are properly cooked only when they are heated at a high enough temperature to kill harmful bacteria that cause food-borne illness."

A meat thermometer is the only accurate way to gauge whether food has been heated thoroughly because it measures the internal temperature of meat and poultry. "Some foods, such as poultry, change only slightly in color even at temperatures up to 170 degrees Fahrenheit, while other foods, such as ground beef, may turn brown at only 135 degrees," says Mills.

Meat thermometers vary, so consumers should know which will work best for their purposes.

Liquid-filled or bimetal (oven-safe) -- These can be used in roasts, casseroles and soups but cannot be used with thin meats. They can be placed in the food while it is cooking, but may give a false high reading. These take one to two minutes to get a reading. They contain mercury, so special caution must be taken to ensure the thermometer is not broken.

Thermistor -- This type can be used with both thin and thick foods. It cannot be placed in the oven while the food is cooking, and it takes 10 seconds to get a reading. Thermistors are available in stores where kitchen items are sold.

Thermocouple -- This digital thermometer can measure the temperature of the thinnest foods. It takes five seconds to get a reading, but is more costly and difficult to find in stores.

Mill says the thermometer should be placed in the thickest part of the food, away from bone, fat or gristle for most meats. For foods irregularly shaped, such as a beef roast, check the temperature in several places for an accurate reading.

"Using an accurate meat thermometer tells you that the food is indeed done and safe," says Mills. "By using a thermometer, you can tell at a glance if the food is done, or estimate how much longer the dish needs to be cooked."

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EDITORS: Edward Mills can be reached at 814-865-2394.

Contact:

Cheryl Anthony cka106@psu.edu 814-863-0938 814-863-9877 fax

Chuck Gill cdg5@psu.edu 814-863-2713 814-863-9877 fax #189