Prime Rib Quesiton

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Original poster
Dec 21, 2010
Powell, TN
Good morning.  I am a long time lurker here and have gotten some great information over the years.  I joined this morning to ask a question about a prime rib smoke for Christmas.  I need to do about 20 lbs.  I have a 30" Masterbuilt and I'm not sure whether (1) 20lb roast will fit or if I should have the butcher cut (2) 10lb roasts.

If I do the 20lber, I'm ready to rock, but if I do 2 roasts, should I anticipate an adjustment in cook time to allow both roasts to reach my desired internal temp of 125F?

Thanks in advance for any help.  Again, this site is a great resource and I look forward to being a more active part of it. 
Welcome to SMF glad you decided to join in.

I think that you would have a hard time getting a 20 lb'er in the smoker. Doing two 10 lb roasts would also take less time. I would ask the butcher to cut them off the bone and tie them back on it sure makes life easier when you go to slice them. Good luck with your smoke and be sure to take some Qview for us.
I doubt if a 20 pound standing rib roast would fit.

I think they are at least 1" in length per pound.

I would think you should get it cut in half, and put one on the second rack from the top, and one on the third, because I'm not sure one will fit on the top shelf. I wouldn't probe them for the first two hours.

You might want to switch them on the shelves later, if one is much ahead of the other.

I have no idea how long that much will take, because I never did that much at once.

My 5 pounder at 230˚ took 3 hours to get to 118˚ and 3 1/2 hours to get to 130˚.

You can review that smoke by clicking on "Prime Rib" in my signature below.

Both ways will work but as Piney said the 20 lb one would take longer. My main question is will the 20 lb cut even fit in your smoker? If it won't fit then there is you answer for sure. If it will fit then you could go either way. Me personally I would cut it in two that way you will have more surface area of the meat exposed for your seasonings and smoke. Either way will work if you can get it to fit in the smoker just make sure you have a digital probe for each roast so they don't get over done. I am doing my first prime rib as well for X-mas. I can't wait. Best of luck to you and make sure you post the Qview. I have a feeling there is going to be a lot of great Qview coming over the holidays.
Can't add anything to the above advice. Welcome to the forum and we look forward to seeing some Q-view. I'm also doing a rib roast for Christmas. Have been doing one for the last several years but this will be the first one I'm doing in the smoker. Looking forward to it.
See why I love this place!!  Less than an hour and 4 replies.  I certainly appreciate it.  I'll have the butcher split it and separate the bone.  I will certainly take some photos and will then read up on the Q-view primer (I'm assuming one exists!)

Thanks again guys, I really appreciate it.
My in laws just dropped off a 7.5 lb roast that we will be making prime rib out of on Sunday and it was big. I can't even imagine how big a 20lb roast would be. I would definately cut it in two or even three if your smoker can't candle it in two pieces. I didn't realize how big a 10lb roast would be. is reader supported and as an Amazon Associate, we may earn commissions from qualifying purchases.

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