I'm doing my go-to Christmas roast this year, utilizing the 500* at 5 minutes per pound method.
A friend of mine is cooking two of them rather than one larger roast for additional end cuts. Seems like a good idea, I like end cuts, but it got me thinking, would this alter the timing of the technique above?

For instance, should 2-5 lb roasts cook at 5 min per pound x 5 lbs rather than cooking for 5 minutes per pound x 10 lbs?

5 lbs x 5 minutes per pound.

get a probe thermometer,

quote:

Originally posted by lyman:
get a probe thermometer,

I have a probe, that's not really how this technique works.

Doesn’t the probe take all the guessing out of it? Cook at 500 till it’s 125-130 internal and then you’re done.

quote:

Originally posted by DaveL:
Doesn’t the probe take all the guessing out of it? Cook at 500 till it’s 125-130 internal and then you’re done.

Ive cooked with and without the probe, I'm not concerned about my ability to cook a rib roast, I'm asking for a friend who is cooking two roasts at the same time.

The technique I'm referring to offers a cook time of 5 minute per pound at 500* then you kill the oven and let the roast continue to cook for 2 hours. This is the method in which the roast will be cooked and the method in which I'm asking for advice.

quote:

Originally posted by MikeGLI:
I'm doing my go-to Christmas roast this year, utilizing the 500* at 5 minutes per pound method.
A friend of mine is cooking two of them rather than one larger roast for additional end cuts. Seems like a good idea, I like end cuts, but it got me thinking, would this alter the timing of the technique above?

For instance, should 2-5 lb roasts cook at 5 min per pound x 5 lbs rather than cooking for 5 minutes per pound x 10 lbs?

You mean "turn it to 500 degrees F and when it reaches that turn the oven off, correct?"

I've used that method with good result on one roast, never two smaller ones. It seems to me each roast stands on it's own since they are not connected, merely next to each other. But then again extra mass in the oven does suck up resources. I'd err on the side of just going with the time based on one roast. There are ways to cook it a bit more if it is too rare, but there's no method to uncook.

The method should still work, just adjust the time to the smaller roast instead of the total weight. While a ten pound roast would be 50 minutes, two five pounders would be 25. I'd still put a thermometer in there to be sure.

Also, this doesn't work with some ovens. I got a new one several years ago that has a built in fan that cools the oven off quickly. I didn't know this beforehand and did the 500X5 method. Two hours later I pulled out a raw roast from a cold oven. I wasn't happy.

quote:

Originally posted by MikeGLI:

quote:

Originally posted by lyman:
get a probe thermometer,

I have a probe, that's not really how this technique works.

Two probes, and you're covered with a backup policy should your 500 Degree @ 'x' minutes per 'x' pounds calculations not work out as planned.

quote:

Originally posted by NavyGuy:
I've used that method with good result on one roast, never two smaller ones. It seems to me each roast stands on it's own since they are not connected, merely next to each other. But then again extra mass in the oven does suck up resources. I'd err on the side of just going with the time based on one roast. There are ways to cook it a bit more if it is too rare, but there's no method to uncook.

Right. I think the concern is the heat soak once the oven is turned off wont be enough as there is double the mass in the oven.

Found this in the link below. Might be helpful.

NOTE: If you have a large roast you plan to split into two, as long as you have plenty of space between them for air to circulate, you can treat them as a single roast. Example: A 16 pound roast split into two 8 pound roasts would cook for 40 minutes.

Perfect Prime Rib

I agree to go with 5 minutes x the smaller and maybe add 10 minutes more.

Gustofer makes a great point. My oven fan cools it down also.

quote:

Originally posted by MikeGLI:

quote:

Originally posted by lyman:
get a probe thermometer,

I have a probe, that's not really how this technique works.

Sure it does. Cook it to the desired temperature. Any timed method is a way around not measuring the actual temperature.

.

I don't know the answer, but I would appreciate hearing how it goes for your friend. While I expect two roasts will take longer, I don't think it will be double the time or even a quarter the time longer.

I would suggest your friend consider baking cookies. Two sheet pans, one above the other can cause cookies to bake to different levels of doneness between the two pans removed at the same time. Hopefully, the roasts will sit side by side and not one above the other.

They should also consider, two slabs of meat of exactly the same weight will have different cooking times due to their internal temperature when placed in the oven, their individual shape, water content, density, etc... With a bone-in Rib Roast, wouldn't each rib influence the cooking process of that specific roast? This is why cooking for a large crowd (think wedding banquet) usually ends up with blah food.

While the time the oven will take to cool down is probably stable, the temperature changes of cooking meat is not linear. There will be temperatures where the meat stays at longer during cooking time. I am trying to locate an article about this that I read several years ago.

I own two wired probe thermometers. I would buy a 3rd for this, but if I only had two ~ I would use one to monitor the smaller roast and the other thermometer setup to monitor the temperature inside the oven since my oven stops providing temps once it is turned off. If your friend realizes towards the expected end of cooking that the smaller roast is not hitting the desired temperature ~ they have the horrifically scarry option of heating up the oven. Two days before Christmas isn't the time to suggest that your friend cook a couple of roasts as a run-through before the big day to lean how this change in technique will go.

I did locate an excellent article that explains how meat cooks and what the internal temperature does to the meat. It's posted on the Science of Cooking website:
www.ScienceOfCooking.com/meat/slow_cooking1.htm#:~:text=160%C2%B0F%2F70%C2%B0,to%20gelatin%20at%20160%2F70.

Another article in Science Direct about Sous vide cooking has a section on the Effects of Heat and Time on Muscle Meat. Not knowing your friend's knowledge, this might also be helpful to them:
www.ScienceDirect.com/science/article/pii/S1878450X11000035#s0070

From what you've posted, it sounds like you enjoy cooking and might like to read it, hopefully it will be helpful for your friend.

Hey, one last thought ~ Is there a friendly neighbor that will be elsewhere for Christmas that would allow your friend to use their oven?

.

quote:

Originally posted by jhe888:

quote:

Originally posted by MikeGLI:

quote:

Originally posted by lyman:
get a probe thermometer,

I have a probe, that's not really how this technique works.

Sure it does. Cook it to the desired temperature. Any timed method is a way around not measuring the actual temperature.

I follow a few pellet grill forums. Its always cook to temperature not time. Everyone ask what time should I start my cook if I want to eat at 6pm. The answer is it depends. Sometimes you get a piece of meat that never cooperates with your schedule.

Once the temp inside the oven gets up to 500 Degrees, it doesn't matter how many roasts are in there, they all are cooking at the same temperature.

quote:

Originally posted by Flash-LB:
Once the temp inside the oven gets up to 500 Degrees, it doesn't matter how many roasts are in there, they all are cooking at the same temperature.

This is correct, as long as the oven remains on. If it's a timing thing where you turn the oven off at a point, having two roasts of 5 lbs instead of one could affect the outcome.

Of course one 10 lb is definitely different than two 5 lb, but I'm sure that's not what you're asking.

Regardless, a probe is always a good idea, as pure timing methods are just best guesses. For example, your roast may start at 32*, 38*, room temperature? Depends on the termperature of your fridge, or your room, or how long you let it sit out, or all three.

We do multiple Prime rib for our fishing league banquet each year. We group them by weight and cook by the individual roast weight (temp probe in each so we can open a door if they're cooking too fast). So in your case the time we'd cook to would be for a 5lb roast.

While yes - properly cooked meat will be cooked to temp - you don't always have that luxury. If you're feeding a large group it's tough to say "we'll eat sometime between 5pm and 10pm - whenever the meat decides it is done" This method tries to combine the two and works ok for large roasts (like a prime rib) that don't need to be cooked to higher temps (like pulled pork or a brisket would). Last year we did 48lbs (three 15 - 17lb roasts). Oven on for 70min (meat was around 50 degrees when we put it in the oven) - shut it off and didn't open the door. They reached temp early so we cracked the door on the oven until the meat temp stalled and then closed again to hold temp since we weren't serving for another 40 min.

quote:

Originally posted by jhe888:

quote:

Originally posted by MikeGLI:

quote:

Originally posted by lyman:
get a probe thermometer,

I have a probe, that's not really how this technique works.

Sure it does. Cook it to the desired temperature. Any timed method is a way around not measuring the actual temperature.

At what point in the cook are you suggesting to probe the meat?