Cooking A Prime Rib

The average bovine has 13 ribs. Some younger ones have only 12 but most mature ones have 13 so I am referring to them when I say that a prime rib roast comprises 7 ribs, starting from the 7th rib at the shoulder and continuing back to the 13th rib at the loin, part of which is the most tender part of meat on the animal.
The reason the loin is so tender is because it is a muscle that is rarely used. The most heavily used and strongest muscles are the toughest cuts of meat.
The prime rib is the piece of meat that rib-eye steaks and rib steaks are cut from. A normal, full 7 rib roast will yield 14 rib-eyes or 7 rib-eyes and 7 rib steaks. The only difference between a rib steak and a rib-eye steak is that the rib-eye does not have the rib bone attached as the rib steak does. When you remove the bone you have a rib-eye.
Many butchers will call a rib steak a bone-in rib-eye. Nevertheless, the rib steak, although it is the exact same cut of meat, should always be cheaper per pound than the rib-eye because you are paying for bone, which obviously, you cannot eat, but many times they are the same price.
The tenderloin is the cut of meat that continues back from the end of the prime rib roast, or 13th rib, along either side of the back and is usually cut into three sections called the sirloin, tenderloin and top sirloin. The tenderloin is the most tender piece of meat on the entire animal and is what the filet mignon is cut from.
A full prime rib roast is a very expensive cut of meat, so it is important to know many things about buying, preparing and cooking one before you ever attempt to do one, because a ruined prime rib roast is a lot of money wasted.
Before cooking a prime rib you’ll need to know how much (how many ribs) you will need to buy as per how many hungry people you are going to feed. You also need to figure an estimated cooking time and you need to know exactly what temperature it needs to be when you take it out of the oven.
The roast will continue to rise 10 degrees in temperature during the resting period. The resting period is usually 20 to 30 minutes and that allows the juices to re-settle into the meat. If you carve a roast without letting it rest, you will lose a lot of juices and your roast will be dry.
So, since the roast will continue to rise in temperature, you will need to take it out of the oven 10 degrees before it reaches your desired temperature for the perfect doneness, whether you want it rare, medium rare, medium, medium well and well done.