Pre-Mature Browning

Due to recent research, USDA now recommends consumers utilize an instant read meat thermometer during the cooking of ground beef patties to insure patties are cooked to an internal temperature of 160° F.  This temperature is high enough to kill bacteria, if they are present in the meat. Notably, this temperature also includes the destruction of the E. coli O157:H7 pathogen, which has been a recent concern.

The recommendation for using an instant read meat thermometer replaces the former suggestion for cooking ground beef until no longer pink in the center or until the juices run clear serving as the visual guide for hamburgers that they have reached the temperature at which bacteria is killed.

Research on premature browning of ground beef conducted by Kansas State University and USDA clearly shows ground beef experiences various color reactions throughout the heating process.  The premature browning effect produces a well-done, internal cooked appearance at a temperature lower than expected.  Therefore, using color alone as the guide for determining the doneness of a ground beef patty can provide a false security for insuring the hamburger was cooked to the safe internal temperature that kills harmful bacteria.

Premature browning is not a sign of bad or low quality meat.  Simply stated, this browning effect is caused by the natural color changes meat experiences when exposed to oxygen. The only drawback of this premature browning comes from assuming the meat is cooked thoroughly when in actuality, it may not have reached the appropriate temperature to kill foodborne pathogens.

As a result, measuring the internal temperature of ground beef is the most accurate, simplest and safest way to insure meat is at 160°F, the proper temperature to kill harmful bacteria and thus, no longer a risk for causing a foodborne illness.  Even at this temperature, the patty center and juices may be pink, brown, or a variation of pink and brown, but the patty is safe if it reached 160°F.

For consumers preparing their own meat, using an instant read thermometer is the best measure to protect their loved ones from foodborne illness.  The people who are most at risk from a foodborne illness include young children, elderly, and those who have weakened immune systems due to illness.  Various thermometers are available where kitchen utensils are sold, including digital instant-read thermometers, small dial instant read thermometers and disposable instant read thermometers.  The large dial thermometers designed for roasts and whole poultry are not suitable for hamburger patties.

At the foodservice level, temperature thermocouples or instant read thermometers can be utilized to accurately determine hamburger patties reached the proper internal temperature.

For testing hamburger patties, the thermometer should be inserted sideways into the patty until it reaches the center and the temperature should reach at least 160°F.  This same thermometer can also be used to measure the temperature of steaks; however, steaks have a minimum temperature requirement of 145°F (medium rare) to kill bacteria.

If you would like more information contact your local health department at ( put your name and number here).