Rib Roast Vs. Prime Rib: Is There Really A Difference?

Most families serve some kind of roast meat for Christmas dinner, but not every family serves the same kind of roast meat. Some will favor turkey, having apparently not gotten enough of it from Thanksgiving the previous month; some will prefer a big, pink, glossy spiral ham. Some will even serve a goose like some kind of Victorian. But for some, you can't beat a juicy, succulent beef rib roast — or is it a prime rib? You never quite got it straight, and your folks use both terms pretty much interchangeably. But there is a difference, right? Well, sort of: like squares and rectangles, all prime ribs are rib roasts, but not all rib roasts are prime ribs.

A "rib roast" refers to a cut of meat taken from anywhere on the rib primal, or the area between the chuck roast (the front shoulders of the steer) and the short loin. Because an entire rib primal could run up to 25 pounds, most of the time you'll just get a chunk of it for your roast. This is one of the most tender cuts of beef on the steer, and it's priced accordingly.

You may have heard beef described as "prime" before, indicating that the USDA gave it its highest quality rating. While few can deny that prime rib is a "prime" cut of beef in terms of desirability, the "prime" in its name actually has nothing to do with quality. Instead, it refers to the "primal" cut, between the sixth and twelfth ribs. (This is also where ribeye steaks are cut from.) All told, it weighs about sixteen pounds, and has some particularly choice marbling, or fat.

So what are the differences between these two cuts? Well, for one, prime ribs are generally more reasonably sized than rib roasts, and usually contain the bones rather than being deboned; that makes them (marginally) more economical. And while both cuts are certainly delicious, prime rib is generally a bit richer-tasting than just a rib roast. (It's not called the House of Rib Roast, after all.)