We have all at some point been guilty of using the phrase, “is it done yet?” Whereas the food may be done or ready according to the person cooking it, or to your liking, that does not always mean it the food is safe.
Unfortunately, you cannot look at a food (i.e. your holiday turkey) and know when it is done. The only way to determine if a food has been cooked to a safe internal temperature is to use a food thermometer.
An early study at Kansas State University found that ground beef may turn brown when cooking before reaching the safe internal temperature of 160 degrees at which bacteria are destroyed. Because of that study, the USDA Food Safety and Inspection Service conducted further research to determine the relationship between brown meat and “doneness.” However, as the research indicated, the color of the meat and the color of the juices are not accurate indicators of “doneness.”
The findings showed that one out of every four hamburgers turn brown before it’s been cooked to a safe internal temperature, and yet, only 6 percent of cooks surveyed checked hamburgers with a food thermometer.
If someone is preparing ground beef patties and is depending on sight to determine food safety by using the brown color as an indicator, he or she is taking a chance that pathogenic microorganisms may survive.
A hamburger cooked to 160 degrees (165 degrees for ground poultry) measured with a food thermometer is safe regardless of color. The term “doneness” is merely subjective and refers to a person’s personal preference according to taste, texture and appearance of the food, rather than safety.
The safe minimum internal temperature that a food must reach when cooked is different depending on the food. Poultry (all types including ground), leftovers and casseroles must be cooked to 165 degrees. Ground meats (beef, pork, veal, lamb) and egg dishes must be cooked to 160 degrees. Pork, fresh ham, and fin fish must be cooked to 145 degrees. If rest times are listed in recipes, be sure to allow cooked food to sit for the recommended time prior to carving or consuming. An easy chart to reference can be found at www.foodsafety.gov.
Various food thermometers are available for purchase depending on your needs. Digital thermometers include thermocouples, thermistor, oven cord thermometer, and thermometer fork combination. Dial thermometers include oven-safe and instant-read bimetallic-coil. Other types of thermometers include single use indicators and pop-up timers. Single use temperature indicators should be used at the end of cooking to determine if a food has reached a safe internal temperature. A conventional food thermometer should always be used in addition to the pop-up timers (often found in poultry) to make sure the temperature is safe.
The thermometer should be placed in the thickest part of the food, away from any bones or fat. Always read the instructions prior to use to determine how far the thermometer has to be inserted in the food to achieve an accurate reading.
Thin foods — such as hamburgers, pork chops or chicken breasts — should be measured using a thermistor or thermocouple. If using an instant-read dial bimetallic-coil food thermometer, insert the probe in the side through the center of the food. Egg dishes and those containing ground meat and poultry should be checked in several places.
Always wash the probes of the thermometer in hot, soapy water by hand after using.
For more information on food safety, please contact UGA Extension in Forsyth County at (770) 887-2418 or visit us online at ugaextension.org/county-offices/forsyth.html. Forsyth County Extension is supported by The University of Georgia, Forsyth County Government, Forsyth County Board of Education, and United Way of Forsyth County.
Barbara Worley is the family and consumer sciences agent, UGA Extension Forsyth County.