By JOE O'CONNELL, cbbqa past President
Updated May 17, 2002
Barbecue cooks must know the rules of food safety.
Many cooks are understandably confused about meat and food safety. Some of the confusion arises because of the confusion between meat safety and meat doneness.
Meat is meat, whether beef, pork, lamb, chicken or fish. Meat usually refers to the muscle of an animal but it can include other non-muscle tissue. For meat safety purposes, meat is meat -- most organisms that are dangerous to humans will grow on or in any kind of meat (with a few exceptions, like trichinosis, described below).
On the other hand, for meat doneness in cooking, different meat and different cuts of meat cook differently. For example, a beef tenderloin is cooked to medium at 140F, while chicken dark meat must reach about 165F to be cooked to medium. These types of differences reflect the fact that different animals and different muscles have different densities and other characteristics.
Consequently, when learning to cook, novices often confuse safety issues and doneness issues, such as, for example, whether chicken has to be cooked to 165°F in order to make it safe or in order to make it done. Moreover, food safety authorities usually overstate the safe cooking temperatures in order to create a "margin of safety," and this causes further confusion.
For example, trichinosis in pork is killed at 137F, but food safety authorities routinely recommend that pork must be cooked to 160F.
There are thus three temperatures that cooks must deal with: the temperature when meat is done, which depends on the type and cut of meat; the temperature when meat is really safe, at which dangerous bacteria are killed; and the temperature when authorities state that meat is safe, which usually includes a wide margin of error.
Bacteria contaminate the surface
The bacteria that are among the most dangerous to humans grow and produce toxins on the surface of meat at temperatures between 40F and 140F (the "danger zone").
Most dangerous bacteria cannot contaminate the interior unless/until after it has contaminated the surface. There seem to be a few exceptions, but they are really just special cases of surface contamination finding its way into the interior, such as:
The absolute rule of meat:
Toss any meat if its surface temperature may have remained in the danger zone (between 40°F and 140°F for more than two hours.
Note that critical temperature is the surface temperature, because that is where the dangerous bacteria grows. Novice cooks sometimes believe that, if the interior is frozen, the surface will remain safe, but this is not true and is highly dangerous. (This is the reason that frozen meat must be thawed in the refrigerator or in the microwave -- it is very dangerous to leave frozen meat to thaw at room temperature.)
Once in the danger zone for two hours, the meat cannot be salvaged. Even cooking it to 500°F will not make it safe, because the danger is not from the living bacteria (most of which are killed at around 140°F) but because, when alive, they produced chemicals (toxins) which cannot be destroyed by heat.