T-bone and Porterhouse Steaks
T-bone and porterhouse are steaks of beef cut from the short loin. Both steaks include a "T-shaped" bone with meat on each side. Porterhouse steaks are cut from the rear end of the short loin and thus include more tenderloin steak, along with (on the other side of the bone) a large strip steak. T-bone steaks are cut closer to the front, and contain a smaller section of tenderloin.
There is little agreement among experts on how large the tenderloin must be to differentiate a T-bone steak from porterhouse. The U.S. Department of Agriculture's Institutional Meat Purchase Specifications state that the tenderloin of a porterhouse must be at least 1.25 inches thick at its widest, while that of a T-bone must be at least 0.5 inches. However steaks with a large tenderloin are often called a "T-bone" in restaurants and steakhouses despite technically being porterhouse.
Owing to their large size and the fact that they contain meat from two of the most prized cuts of beef (the short loin and the tenderloin), T-bone steaks are generally considered one of the highest quality steaks, and prices at steakhouses are accordingly high. Porterhouse steaks are even more highly valued owing to their larger tenderloin.
In the United States, the T-bone has the meat-cutting classification IMPS 1174; the porterhouse is IMPS 1173.
In British usage, followed in Commonwealth countries, porterhouse refers to the strip steak side of a T-bone steak, while the tenderloin side is called the fillet.
T-bone and porterhouse steaks are suited to fast, dry heat cooking methods, such as grilling or broiling. Since they contain a small amount of collagen relative to other cuts, longer cooking times are not necessary to tenderize the meat. The bone also conducts heat within the meat so that it cooks more evenly and prevents meat drying out and shrinking during cooking. The meat near the bone will cook more slowly than the rest of the steak, and the tenderloin will tend to reach the desired temperature before the strip.