Temperature is a description of how thoroughly cooked a cut of meat is based on the colour, juiciness and internal temperature when cooked. The gradations of cooking are most often used in reference to beef (especially steak and roasts) but are also applicable to lamb, pork, poultry, veal, and seafood (especially fish).
Gradations, their description, and the associated temperature ranges vary regionally from cuisine to cuisine and in local practice and terminology.
The table below pertains to beef and lamb. In lieu of gradations and ranges, some authorities recommend a temperature of at least 63°C for beef, veal, lamb steaks and roasts in order to prevent foodborne illness.
The interior of a cut of meat will still increase in temperature 3–5 °C after it is removed from an oven or other heat source. The meat should be allowed to “rest” before being served, which allows for the juices in the centre to return to the edges. The whole meat, and the centre will also continue to cook slightly as the hot exterior continues to warm the comparatively cooler interior.
The exception is if the meat has been prepared in a Sous-vide process, as it will already be at temperature equilibrium. The temperatures indicated below are the peak temperature in the cooking process, so the meat should be removed from the heat source a few degrees cooler.
Degree of Doneness
The following descriptions for doneness are demonstrated with a grilled beef steak shown at varying stages of doneness. The same criteria for colour, texture, juiciness, and internal temperature can be applied to beef cooked with other methods such as broiling, pan-frying, or roasting. The best method for determining the desired doneness is with the use of a meat thermometer [brclearboth]
Even though harmful bacteria are usually only on the surface of whole beef cuts, there is growing concern that bacteria may be present in the internal portions of the meat as well, which is why it is now recommended that whole beef cuts be cooked to an internal temperature of not less than 63°C. Traditional guidelines for doneness state that beef cooked very rare, rare, or medium-rare should have an internal temperature ranging between 46°C to 60°C. Many people prefer beef cooked rare (especially steak), but this decision is up to the consumer and is certainly not recommended by some authorities.
It is important to remember that after a cut of beef is removed from the heat source, the internal temperature will continue to rise. Although thin beef cuts, such as steaks, are usually served within a short time after removal from a grill or broiler oven, thicker cuts, such as roasts, benefit from a “resting” period before slicing and serving. The resting period, which may range between 10 to 30 minutes, depending on the beef cut, allows the juices to redistribute and allows the internal temperature to rise because of residual heat. The internal temperature will increase 3° – 8°C during the resting period, which allows the beef cut to be removed from the heat source when the internal temperature is lower than the desired doneness. A Meat Thermometer should be used to check the internal temperature of the meat to ensure proper doneness.
Whole beef cuts usually have bacteria only on the surface, but it is possible for harmful bacteria to be present in the internal portions, so cooking the meat to an internal temperature of 63°C is sufficient to kill the bacteria. (The surface of the meat will be at a much higher temperature; usually 71°C or above).
Bacteria such as E. Coli may be present on any cut of beef, but it is most common on minced beef because the grinding process may distribute the bacteria throughout the meat. Minced beef must be cooked until the internal temperature reaches a minimum of 71°C to ensure that dangerous bacteria are destroyed.
Minced beef dishes, such as meatloaf, should be checked for doneness with a meat thermometer. This is especially important when the meat has been blended with dark sauces that can mask the colour of the meat, making it difficult to determine if any pink colour remains, which would indicate that the minced beef is not fully cooked.
As meat is cooked, it turns from red to pink to gray to brown to black (if burnt), and the amount of red liquid, myoglobin (not blood), and other juices decreases. The colour change is due to changes in the oxidation of the iron atom of the heme group in the myoglobin protein: raw meat is red due to myoglobin protein in the muscles, not hemoglobin from blood (which also contains a heme group, hence the colour). Searing raises the meat’s surface temperature to 150 °C, yielding browning via different reactions: caramelisation of sugars, and the Maillard reaction of amino acids. Raised to a high enough temperature, meat blackens from burning.
Well done cuts, in addition to being brown, are drier and contain little or no juices. Note that searing (cooking the exterior at a high temperature) in no way “seals in the juices” – water evaporates at the same or higher rates as unseared meat. Searing does play an important role, however, in browning, a crucial contributor to flavour.