Determining Doneness of Meat

Determining the Doneness of Meat

A number of changes occur in meat during cooking, and multitude of factors effect the cooking times of meats: the effects of carry-over cooking; differences in the type, size, and cut of meat; the presence of bones, which conduct heat faster than flesh, or of fat, which acts as an insulator; the actual oven temperature; the temperature of the meat before heating, and variations in the degree of doneness preferred by the preparer.

Time/Weight Charts. Time/weight charts are useful in estimating roughly how long it will take to cook a piece of meat, but are unreliable if used alone because of the factors cited above. Instead, a combination of criteria is used to determine the doneness of meats. The criteria include time/weight charts along with color changes, internal temperature, and touch.

Color Changes. Meat pigments change color as the meat is cooked. Doneness can be determined by observing the following colors in red meats:

• Rare. Strong red interior. Rare meat does not reach a final internal temperature considered microbiologically safe.
• Medium. Rosy pink interior and not quite as juicy as a rare piece of meat.
• Well done. Brown interior. No traces of red or pink left. Moist, but no longer juicy.

Veal and pork are known as “white meats”, in part because they change from a pinkish to a whiter color as they are heated to the well-done stage. According to the USDA, pork should be heated at least to an end-point temperature of 160^oF (71^oC). Color may not be a good indicator for doneness in meat from older swine, which is often grayish-brown rather than pink. It is not recommended that color be used to judge the doneness of hamburger, either, because of the risk of E.coli contamination.

Internal Temperature. Using a meat thermometer is the most accurate method of determining doneness. There are several different styles of meat thermometers in the market, with some being inserted into meats before heating and others, such as instant-read thermometers, that can be inserted at any time. The thermometer should be inserted into the thickest portion of the meat and in such a way as not to touch any fat or bone. Meat thermometers should be thoroughly sanitized after each use. The final internal temperatures according to the USDA for beef are as follows:

• Rare: 136-140^oF (58-60^oC)
• Medium: 160-167^oF (71-75^oC)
• Well done: 172-180^oF (78-82^oC)

Aside from pork, which must reach 160^oF (71^oC), most other meats are expected to reach an internal temperature of at least 140^oF (60^oC). In January 1993, following an outbreak of E. coli, health departments increased the preparation temperature for hamburgers served by eating establishments form 140^oF (60^oC) to 160^oF (71^oC).

When measuring internal temperature, it is important to adjust for carry-over cooking. This can result in an average temperature increase of 10^o to 15^oF (6^o to 8^oC) for average-sized roasts. Very large roasts can have as much as a 25^oF (14^oC) increase in temperature, while small cuts may rise only 5^oF(3^oC) in temperature. To adjust for this carry-over cooking, most roasts should be removed from the oven when the internal temperature is 10^o to 15^oF (6^o to 8^oC) below the final desired degree of doneness. Meat cooked at low temperature such as 200^o to 250^oF (93^o to 121^oC) will experience only minimal carry-over cooking. Depending on their size, roasts should be allowed to stand for 15 to 30 minutes in order to distribute the heat and juices.

Touch. Doneness can be determined by the firmness of the meat. Some meat cuts such as steaks and chops can be judged for doneness based on their color and firmness. Pressing lightly on the center of the lean tissue can help to determine whether the meat is rare, medium, or well done. This technique takes a fair amount of experience to master and is most often used by professional chefs who frequently prepare steaks.