I have a five pound prime rib that I want to make. I've been using sous vide for a year and I love it. Modernist Cooking is my go-to site, but I'm confused. I see 134 degrees for no more than 10 hours here, and 125.6 degrees at 24-36 hours on another site that I don't trust as much. But that site shows edge-to-edge medium rare that they torch for crispness like I will. I wonder if it's too soft though. Please help? Pretty please?
With the holidays in full swing, I've been getting a lot of questions on the best way to cook prime rib. Everyone wants to impress their family at holiday dinners, and prime rib is a great way to do it...provided you cook it properly. My family and I almost always do prime rib for our Christmas dinner and now with sous vide it's incredibly easy and convenient to make.
Based on my research and experience at home, here's everything you need to know about sous viding prime rib for your next family dinner. If you are looking for more information about prime rib in general, or prefer a more traditional way to cook prime rib, I highly recommend reading the Serious Eats article discussing it.
The temperature you cook your prime rib at will depend entirely upon the preferences of you and your fellow diners. I've cooked mine at anywhere from 131°F to 141°F (55°C to 60.5°C) to see how the marbling reacts to cooking at a higher temperature. Even though they all were very flavorful and tender I now almost exclusively cook mine at 131°F (55°C) for a nice medium-rare. I wouldn't go above 137°F (58.3°C) unless everyone at the table like it at least medium.
One of the main issues when serving beef at a large gathering is trying to accommodate all the different levels of "doneness" that people prefer. The most convenient way I've found to keep everyone happy is to cook the roast at the lowest temperature people prefer. Then I divide up the beef into sections based on the doneness people want. During the searing phase, I just sear the more well done sections longer, until the middle reaches about the color they want. This way people who like a rare or medium-rare middle are happy and there's very little extra work you need to do to please the others.
Before we get into how long prime rib needs to sous vide for, I wanted to discuss how to seal it, as it will change the timing. There are two main ways to prepare prime rib for sous vide. The first is to cook it whole, or in large pieces (3 or more ribs), and the other is to cut it into slabs, usually 1 or 2 ribs per slab. Each preparation method has pluses and minuses. I've cooked both ways and enjoyed them, but now I almost always cut it into slabs.
Regardless of how you cook it, you can either leave the bones in or remove them. With sous vide it is mainly an aesthetic choice and doesn't affect the end flavor or texture much at all. Also, for short cooks like prime rib you usually don't have to sterilize the outside of the meat, but if you often run into issues with meat turning smelly, it doesn't hurt to dip it in boiling water or use a torch on it before bagging it.
Cutting the prime rib into slabs, usually consisting of 1 to 2 bones, offers several advantages.
The first advantage is a reduction in cooking time. The thickness of the slabs is always thinner than the thickness of the entire roast. This helps reduce the cooking time, and also results in more even cooking because the outside of the slab and the center of the slab and will both reach temperature, and start tenderizing, much closer together.
Another advantage is the ability to easily serve slabs at different temperatures. This can be accomplished either through using a separate sous vide bath set to a higher temperature, or searing certain slabs for longer.
Having separate slabs also lets you sear the entire slab, not just the edges. This results in a wider searing area and more flavor from the Maillard reaction.
The main disadvantage to cooking slabs is the lack of presentation. You lose out on the large, perfectly seared roast sitting on the table. You can still do many great presentations ideas, but it's not always the same. One trick I've learned is that you can normally reassemble the slabs on a plate into the initial roast shape, similar to how porterhouse steaks are served at fancy steak houses. This gives you many of the benefits of using slabs, but also lets you use you the traditional presentation many people love. Plus it greatly speeds up carving at the table since the slabs are already cut!
The main advantage to leaving the prime rib whole is for presentation. A large prime rib roast, nicely seared, and sitting on a carving plate in the middle of the table is a great way to get everyone excited for dinner. In my opinion that's really the only major advantage to leaving it whole.
A disadvantage to cooking the prime rib whole is the difficulty in serving it at different temperatures to different people. If someone prefers medium doneness, it's really inconvenient to carve off a slab for them and sear it for longer. Plus it begins to break down the presentation, which is the main benefit of leaving it whole to start with.
If you really like using a crust with your prime rib, then leaving it whole does give you more time and leeway in the oven when you bake the crust on.
Whole prime rib roasts will also need to sous vide for much longer. The thickness of the whole roast is usually around 3" (75mm), which takes much longer to heat through, up to 2 to 3 times longer, than a 1" or 2" slab (25mm or 50mm). You will also have a slightly uneven cook with the roast, because the outside of the roast comes up to temperature several hours before the middle does, which will result in a more tender outside than middle.
Prime rib is already a tender cut so you don't need to sous vide it for a long period of time. Prime rib roasts are also generally a uniform size, which helps with timing. I normally sous vide my prime rib for 5 to 10 hours. It's long enough I don't have to worry about specific timing and also helps to tenderize it slightly. It's also short enough that it easily fits into my busy schedule around the holidays. Prime rib is less finicky to time differences than some cuts due to the high marbling, this makes it ideal for the holidays, when dinner can get pushed back. I usually shoot for an 8 hour cook, which gives me some leeway on either side in case dinner is moved up or delayed.
For a more exact temperature, you can cook by thickness using my sous vide ruler. If you are doing slabs, a 1" thick (25mm) slab will take about an hour from the fridge and a 2" slab (50mm) will take around 3 hours. Anything much bigger than 2" is cooked about the same time because the thickness of the roast will be more than the slab. A 3" thick roast will take about 3.5 hours from the fridge (less than a 3" slab because spherical foods cook faster).
The seasoning you use on your prime rib depends on the flavor profile you are aiming for in the final dish. Most of the usual dry prime rib seasonings work fine and most woody herbs are great. Fresh garlic and onion, and some herbs, don't translate as well and shouldn't be used. I like using a cumin, paprika and light salt rub with some fresh rosemary or thyme. Some people prefer to omit the salt, but I like the slightly beefier flavor it adds.
If you want to add garlic or onion, it's best to do it as a finishing step.
Your method for finishing the prime rib will depend a lot on how you sealed it.
For slabs, I usually sear them in a hot pan or using a blow torch. It's generally the best way and maximizes the sear without overcooking them. Some people also love to deep fry the slabs, which results in an extra crunchy exterior, and it is a great option if you don't mind dealing with the oil. Either way, make sure you thoroughly dry the prime rib once you remove it from the sous vide bags.
For a whole roast, there's two options, depending on if you want a flavored crust or not.
If there is no crust then a torch is your best option to sear the roast. If you don't have a torch then you can use a hot pan. It can be hard to sear the prime rib in a pan due to its shape, but with some micromanaging you can usually get a decent sear on most of it. Make sure you dry the prime rib off before searing it. You can also sear the roast in the oven, as described below.
If you want a flavored crust on the roast I'll usually turn to the oven. Once you dry off the roast you can smear on the flavored paste that will make up the crust. Place the roast in a preheated 450°F to 500°F oven (232.2°C to 260°C) for 10 to 30 minutes, until the crust sets. Depending on the crust, or in the case of not having a crust, using the broiler setting also works great. You can then remove the prime rib and serve it. Finishing in the oven will create a little bit of a "bullseye" effect since the outside of the roast will cook a little more, but it'll still be much less than from a traditionally cooked prime rib.