Whether you buy your ground beef at the supermarket or you grind your own beef at home, it's important to cook ground beef thoroughly. This is because undercooked ground beef can harbor dangerous bacteria like E. coli and Salmonella .
Foods become contaminated with bacteria in any number of ways. In the case of meat, it can happen anywhere along the supply chain, from the farm where the beef are raised to the supermarket or butcher shop where you buy it. You might even contaminate it yourself at home via your utensils or a cutting board (see Cross-contamination), by not washing your hands or whatever.
Ground Beef Should be Cooked Well Done
When it comes to cooking ground beef, 165°F means well-done. That means that you should never see any pink in the middle of your burger. That's right, the days when it was safe to eat a medium-rare hamburger are sadly behind us.
The way to achieve well-done burgers is by cooking them for three to four minutes per side, depending on how thick they are and how hot your grill or pan is. You can use an instant-read thermometer to check the temperature to make sure. But once you've cooked your burgers this way a few times you'll get the hang of it.
Ground Beef is Different from Steak
You might be saying to yourself, "Why do I have to cook my burgers well-done when it's okay to cook my steaks medium rare? Beef is beef, right?"
Well, yes and no. For one thing, in the case of a steak or roast, these bacteria only hang out on the surface of the meat, not the interior. And since the surface of a steak or roast is the first part that gets cooked, it's safe to cook a steak or roast medium rare.
Ground beef, on the other hand, starts out as a large primal cut like beef chuck. Let's say there are bacteria on the surface of the meat. When it goes through the grinder, all that surface area gets swirled throughout, so any bacteria that were on the surface are now uniformly distributed throughout the meat.
It's worth noting that bacteria are now uniformly distributed throughout the meat grinder, too, which means the next piece of meat that goes in is also going to be contaminated. You really have to ask yourself, how confident are you that the butcher is thoroughly cleaning and sanitizing that meat grinder after each use? In a busy butcher shop, the answer is most likely, not very confident. (Read more about why you need to have a great butcher.)
Cook Ground Beef to 165°F
The way you get confident is by cooking your ground beef to a minimum internal temperature of 165°F. That way, you can be certain to kill the bacteria on the surface as well as any inside the burger.
Note that even if you grind your own burgers at home, this does not give you a free pass to cook your burgers less than well-done. To be sure, grinding your own burgers does offer greater peace of mind as far as what's going into your ground beef. If you grind it yourself, you know exactly what's in it, which is more than you can say for a lot of commercially ground beef. In some cases, a package of ground beef that you buy at the store might not necessarily have come from a single cow. Think about it.
If that's a little scary, but you're not up for grinding your own meat at home, you can have your butcher grind a piece of beef chuck for you right there at the butcher shop. A good butcher will be happy to do this for you (but see the caveat about cleaning the meat grinder mentioned earlier).
What About Mad Cow Disease?
Grinding your own meat (or having the butcher do it) is also a good way to avoid things like mad cow disease, which starts off with sick cows, which is bad enough, but then bits of those cows that weren't supposed to be in the meat, like spinal cord tissue and what not, get mixed in by mistake or carelessness or whatever. Not pleasant to even think about, let alone eat.
It should be noted that even cooking your ground beef to 165° is not sufficient to prevent mad cow disease. That's because mad cow isn't caused by a bacteria but rather a kind of abnormal protein. Fortunately, mad cow isn't too common these days thanks to stringent testing and other regulations implemented by the USDA.
In any case, the main issue with cooking ground beef safely revolves around the issue of grinding surface bacteria into the interior of the meat. Cooking ground beef to a minimum internal temperature of 165°F will help you avoid a case of food poisoning from your burgers.