How Long to Smoke Prime Rib
110°C (225°F) then sear
35–45 min per kg • Internal: 54°C (130°F) medium-rare
Doneness Guide
| Level | Internal Temp | Cook Time | Result |
|---|---|---|---|
| 2 kg (4.4 lb) — 2 bone | 54°C (130°F) | 1.5–2 hours + sear | Serves 4. Good for a small dinner. |
| 3 kg (6.6 lb) — 3 bone | 54°C (130°F) | 2–2.5 hours + sear | Serves 6. The most popular size. |
| 4 kg (8.8 lb) — 4 bone | 54°C (130°F) | 2.5–3.5 hours + sear | Serves 8. Great for a holiday feast. |
| 5 kg (11 lb) — 5 bone | 54°C (130°F) | 3–4 hours + sear | Large roast. Serves 10. |
How to BBQ How Long to Smoke Prime Rib
1
Choose a bone-in standing rib roast for the best flavour. Ask the butcher to french the bones for presentation.
2
Season generously with salt, pepper, garlic, and fresh rosemary. Let it come to room temperature for 1 hour.
3
Set smoker to 110°C (225°F). Use a mild wood — oak, cherry, or pecan.
4
Place bone-side down on the grate. Insert a probe into the thickest part.
5
Smoke until the internal temperature reaches 49°C (120°F) for medium-rare (it will rise during rest).
6
Remove and rest for 20–30 minutes. Meanwhile, preheat your grill or oven to maximum.
7
Sear at high heat (260°C/500°F) for 5–8 minutes to create a crust. This is the reverse sear method.
8
Slice between the bones and serve with horseradish cream and pan drippings.
Pro Tips
- Reverse sear method (smoke low, sear high) gives the most even doneness throughout.
- Pull the roast 5°C below your target temperature — it will continue to rise during the rest.
- A 3-bone roast (about 3kg) serves 6 people generously.
- Don't over-smoke prime rib. Mild smoke for 2–3 hours is all you need. The beef flavour should dominate.
- Save the bones for the best beef stock you'll ever make.
Resting Time
Rest for 20–30 minutes after removing from the BBQ. This allows juices to redistribute for a juicier result.
Frequently Asked Questions
How long to smoke a 3kg prime rib?
At 110°C (225°F), a 3kg prime rib takes about 2–2.5 hours to reach 49°C internal, plus 5–8 minutes searing and 20–30 minutes resting.
What temperature should smoked prime rib be?
For medium-rare (recommended): pull at 49°C, rest to 54°C (130°F). Medium: pull at 54°C, rest to 60°C. Well done is not recommended for prime rib.
Do you need to sear smoked prime rib?
The high-heat sear is optional but highly recommended. It creates a beautiful crust that contrasts with the tender, smoky interior.