The best way to make a hamburger is debatable. In my opinion adding Swiss cheese, pickles, onions, and mustard to a burger nearly perfects it. The one other ingredient? Temperature.
Cooking burgers to 160°F is the only sure way to tell that it is fully cooked. Cooking hamburgers to 160°F kills unwanted microorganisms such as E. coli O157:H7, a deadly ingredient. The U.S. Center for Disease Control and Prevention estimates 61 deaths a year from E. coli, and thousands more ill. Ground beef was recalled 19 different times in 2007 for E. coli contamination.
E. coli O157:H7 loves hiding in the intestines of animals, such as cows. During slaughter, if workers do not follow safe practices it can get onto the cuts of meat. Steaks can be cooked to varying degrees of doneness because any potential for microorganisms exists only on the surface. However, with ground beef the muscle is mixed up and the organisms are spread throughout the meat.
When cooking, don’t rely on the burger’s appearance to tell if it is done. Many people think a burger that is no longer pink is a done burger. This is not the case as pointed out in many studies (here, here, and here). Sometimes burgers look done well before they hit 160°F.
To measure the temperature of a burger, go out and buy a tip sensitive digital thermometer. Remove the burger from the grill or stove and insert the thermometer into the side of the meat all the way to the center. Wait until the thermometer reads 160°F before serving. Add the toppings of your choice, and enjoy!
References
Hunt, M.C., O. Sørheim, E. Slinde. Color and Heat Denaturation of Myoglobin Forms in Ground Beef. Journal of Food Science Volume 64 Issue 5 Page 847-851, September 1999.
http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-2621.1999.tb15925.x?prevSearch=authorsfield%3A%28M.C.+Hunt%29
Ryan, Suzanne M., Mark Seyfert, Melvin C. Hunt, Richard A. Mancini. Influence of Cooking Rate, Endpoint Temperature, Post-cook Hold Time, and Myoglobin Redox State on Internal Color Development of Cooked Ground Beef Patties. Journal of Food Science. Volume 71 Issue 3 Page C216-C221, April 2006
http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-2621.2006.tb15620.x?prevSearch=authorsfield%3A%28M.C.+Hunt%29
Seyfert, M., R.A. Mancini, M.C. Hunt. Internal Premature Browning in Cooked Ground Beef Patties from High-Oxygen Modified-Atmosphere Packaging. Journal of Food Science. Volume 69 Issue 9 Page C721-C725, December 2004
http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-2621.2004.tb09923.x?prevSearch=authorsfield%3A%28M.C.+Hunt%29