If you ask anyone what their favorite cut of steak is, they're likely going say Ribeye.
However not many people realize that Prime Rib and Ribeye both come from the same place on the animal.
While they come from the same beef primal, they look, taste, and are cooked very differently.
The main difference between prime rib and ribeye is in their method of cooking. A Ribeye steak is cooked over high heat and a prime rib is slow cooked.
Prime rib and ribeye also differ in terms of their size, taste, and general economics.
A ribeye steak is typically 1 - 2 inches thick and usually weighs 8 to 16 oz. A whole bone-in prime rib is the width of seven ribeyes and weighs anywhere from 14 to 22 lbs.
In terms of taste, you won't find significant differences as they're from the same area of the steer. Again, the main difference in flavor stems from how they're cooked/prepared.
Ribeye steak is typically salt and peppered and then reverse seared over high heat. With prime-rib you'll often see herbs and spices used to develop an extraordinary crust (my Mom likes to inject garlic cloves) and then the meat is slow roasted under low heat.
In terms of economics, a prime rib is going to cost you more money than buying a single ribeye steak.
For example, we can look at two places I frequent for beef online:
| Meat Provider | Ribeye Roast Cost | Ribeye Steak Cost |
|---|---|---|
| Wild Fork Foods | $147.27 (6.7 lbs - USDA Prime) | $17.49 (0.7 lbs - USDA Choice) |
| Snake River Farms | $255 (5 lbs - Waygu Black Grade) | $75 (0.94 lbs - Waygu Black Grade) |
There are three major muscles that make up a ribeye steak. They are as follows:
These muscles are held together by a tender sinew membrane and large swaths of fat.
To break down these muscles, I've highlighted them in blue below:
The Longissimus Dorsi or the eye of ribeye is the meatiest portion. All ribeyes have an eye - it is the center (or eye) of the cut.
The rib primal isn't a heavily exercised muscle and will collect a lot of intramuscular fat. Most of this marbling happens in the longissimus dorsi.
The eye is surrounded by two kernals of fat called the spinalis dorsi and the complexus.
The Spinalis Dorsi is the cap of the ribeye. Of the three muscles, the Spinalis has superior intramuscular fat.
Without knowing it, most folks would likely find this part of the steak to be the most tender and flavorful part of the entire steak.
The Complexus is the smallest muscle of the ribeye. Depending on which rib (between 6 and 12) you receive, it may not even be present. For instance, a cut close to the front will receive a small piece of the complexus - literally a bite or two.
The spinalis and complexus are very similar, however you get significantly less of it.
A steer has 13 ribs per side. When a Butcher refers to these ribs, they start at the front of the animal and work their way back.
The first five ribs (1 - 5) are found in the beef chuck, the next 7 (6 - 12) are in the rib primal, and the 13th rib is part of the loin. This is also why there are so many different types of beef ribs.
A proper prime rib comes from the best part of a steer's rib - this is generally found in the middle - between rib bones 6 - 12.
Prime rib can also be referred to as a rib roast or standing rib roast - as the bones are standing as the meat roasts.
A whole prime rib or a seven-rib roast can weigh anywhere from 14 to 22 lbs; Not only is this a lot of meat, it is also very expensive.
As a result, Butcher's will divide the roast into two smaller roasts - called a first and second cut.
This area of the rib is prime because it has a thick fat cap and heavily marbled meat. This is the reason prime is used - not because the meat is USDA Prime Grade.
If we look at the United States Department of Agriculture (USDA) Food Standards and Labeling Policy handbook, we're told:
PRIME RIB OF BEEF OR STANDING BEEF RIB ROAST FOR PRIME RIB:
USDA, Food Standards and Labeling Policy handbook, pg. 146.
These products do not have to be derived from USDA prime grade beef.
There are essentially two schools of thought when it comes to cooking prime rib:
Either method works. The goal with both is to develop a great outer crust and a red center.
The way my Mother does is it (Her roast is pictured above) and how I was taught is to sear first and then roast in the oven until Medium-rare.
A ribeye is a beef steak that comes from the rib primal or the cylindrical muscle that is close to the steer's rib.
A true rib eye steak is just the center longismissus dorsi muscle with the other two muscles and fat removed.
However, ribeye is sort of a catch-all term that's used to refer to this type of beef steak.
There are a few different ways to cut a ribeye steak. However, as a generalization ribeye steak is either bone-in or boneless.
When the bone is left in, it's commonly called a cowboy steak. When the bone is left to be long and is frenched, it's called a Tomahawk steak.
Like most other cuts of steak, ribeye steak is cooked over high heat.
The conventional way to cook a steak is to sear over high heat and then to put the steak in the cool zone to come up to a desired internal temperature.
My preference for cooking steak is to do the above in reverse; What's referred to as a reverse sear.
In this case, the steak is placed in the cool zone and allowed to come up to near the finish temperature.
For example, if your goal is medium rare, you might come up to a measured internal temperature like 125-130F, then sear in the hot zone. The steak should finish at around 130 - 135F or medium rare.
This is also the reason resting steak can be problematic. If you opt to rest too long, you risk carry-over cooking (the surface temperature will carry over to the internal temperature) and serving a steak that goes from Medium-rare to medium pretty quickly.
