||This article needs additional citations for verification. (December 2012)|
|Beef cut:||Short Loin + Tenderloin|
|Steak type:||T-bone steak|
The 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 (32 mm) thick at its widest, while that of a T-bone must be at least 0.5 inches (13 mm). However steaks with a large tenderloin are often called a "T-bone" in restaurants and steakhouses despite technically being porterhouse.
Due 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 due to their larger tenderloin.
In the United States, the T-bone has the meat-cutting classification IMPS 1174; the porterhouse is IMPS 1173.
"Porterhouse" Etymology 
The origin of the term "porterhouse" is surprisingly contentious, with several cities and establishments claiming to have coined it. The Oxford English Dictionary traces the etymology from proprietor Martin Morrison serving large T-bones in his Pearl Street, Manhattan "Porter House" around 1914, while noting the lack of contemporary evidence to support the tale. This origin story gained traction in the late 19th century, but others contend a Cambridge, Massachusetts, hotel and restaurant proprietor named Zachariah B. Porter lent his name to the cut of beef, and others claim the steak takes its name from various 19th Century U.S. hotels or restaurants called Porter House, such as the popular Porter House Hotel in Flowery Branch, Georgia.  There is no known contemporary evidence that any particular establishment is related to the steak.
Anatomy of the T-bone 
To cut a T-bone from butchered cattle, a lumbar vertebra is sawn in half through the vertebral column. The downward prong of the 'T' is a transverse process of the vertebra, and the flesh surrounding it is the spinal muscles. The small semicircle at the top of the 'T' is half of the vertebral foramen.
T-bone and porterhouse steaks are suited to fast, dry heat cooking methods, such as grilling or broiling. Due to their relative lack of collagen, 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 level of doneness before the strip.
Bistecca alla Fiorentina 
Bistecca alla fiorentina, or 'beefsteak Florentine style', consists of a T-bone traditionally sourced from either the Chianina or Maremmana breeds of cattle. A favorite of Tuscan cuisine, the steak is grilled over a wood or charcoal fire, seasoned with salt, (sometimes with black pepper), and olive oil, applied immediately after the meat is retired from the heat. Thickly cut and very large, "Bisteca" are often shared between two or more persons, and traditionally served very rare, sometimes garnished with lemon wedges, (if not accompanied by red wine), and accompanied by Tuscan beans as a side dish. An early recipe dictates: 1/1,5 kg, 3 fingers thick, 3-5 minutes grilling per side (flipping it only once) and 5-7 minutes vertically standing on its bone so as to make the blood drain out.
Costoletta di Vitello alla Milanese 
The same cut of meat, but from the calf, is used in the famous dish Cutlet of Veal in the Milan Style, for which carefully chosen 1.5 cm-thick cuts are battered in fresh breadcrumbs and gently fried (sautéed) in abundant clarified butter with salt. This is a favored dish in Italy.
See also 
- e.g. Zachariah B. Porter of the defunct Porter House hotel in Porter Square, Cambridge, Massachusetts "When Cattle Was King". Retrieved 2007-06-25.; Martin Morrison of a New York City porter-house proprietor, "The Big Apple: Porterhouse Steak". Retrieved 2007-06-25.; the Porter House Hotel of Flowery Branch, Georgia "University of Georgia Better Hometown Program "Flowery Branch"". Retrieved 2008-04-13.; "North Georgia Mountain Travel Association Trivia". Retrieved 2008-04-13.
- Oxford English Dictionary s.v. 'porterhouse' C2.
- Delia Smith:Lamb
- LBC:Cooking in the credit crunch
- Waverly Root, The Food of Italy, 1971, ISBN 0-394-72429-1.
- PDF (687 KiB)
Porter House name origin article: http://mentalfloss.com/article/22382/how-9-cuts-meat-got-their-names#ixzz2RIm9KYAT