It's tender, juicy and delicious - but a prime rib (also known as a standing rib roast) is an expensive cut of meat! This means that's it's very important to get your cooking temperatures right for perfect results every time.
What is a prime rib?
Taken from the rib primal cut, this flavorful meat has a layer of fat on the outside and is marbled throughout. It's all the fat that gives the prime rib is mouthwatering taste and texture, so resist any urge to cut it away - your taste buds will thank you (even if your waistline doesn't!).
Temperatures for cooking prime rib
Start by searing the meat at a temperature of 450°F for 15 minutes. Then turn the oven down to 325 °F for the remainder of the cooking time.
The meat should stay uncovered throughout, but you can keep it juicy by basting it with the cooking fat every 30 minutes.
To calculate an approximate cooking time, allow 12 minutes per pound of meat. Around 45 minutes before you think the meat will be cooked, start checking it with a meat thermometer. Make sure you don't wait too long, or you may find that your roast is overcooked.
Prime rib internal temperatures
- If you like your prime rib rare, then the final temperature should be in the range of 120 to 125°F.
- For a medium prime rib, aim for a final temperature of between 130°F and 135°F.
- For a well-done roast, the final temperature needs to be between 140 and 145°F.
We recommend taking your prime rib roast out of the oven when it's about 10 degrees less than the final temperature you want to achieve. That's because the internal temperature will rise by around 10 degrees while the meat is resting.
For a crowd-pleasing prime rib...
Different people have different ideas as to how their meat should be cooked, so if you are cooking for several people you need to prepare the meat in a way that will suit everyone!
The best option is to take your prime rib out of the oven when it reaches a temperature of 120°F. Cover it loosely with foil and leave it to rest for 15 to 20 minutes. This should give you a medium-rare roast, which will (hopefully) please all your guests!
Why a thermometer is important
When you're cooking a prime rib roast it can be tempting to follow the recipe's suggestion for the oven temperature and timing, and assume that your meat will be roasted to perfection as described in the recipe.
Unfortunately, this isn't always the case.
Oven temperatures can vary considerably, and the starting temperature of the meat comes into play too! If the recipe creator rested their prime rib at room temperature for a while before roasting - but you put yours into the oven straight from the refrigerator - then yours will take a little longer to cook.
In fact, cooking prime rib straight from the refrigerator means that it may not cook evenly, so it's not something we'd recommend. The best option is to take the meat out of the refrigerator 2 to 4 hours before you plan to cook it (the time will depend on its size).
To take the temperature of a prime rib...
Push your meat thermometer into the thickest part of the meat - it shouldn't be touching the bone, or resting in fat.