Overview

Smoke a leg of lamb low at 250°F (121°C) over red oak, then finish hard over a live coal bed for a crisp crust and juicy, even interior.

Ingredients

• Leg of lamb, 6–8 lb (2.7–3.6 kg), bone‑in or 5–6 lb (2.3–2.7 kg) boneless/netted
• Kosher salt 2–3 tbsp (28–42 g), or 0.8–1.2% of meat weight
• Freshly ground black pepper 2 tbsp (14 g)
• Garlic, minced 6–8 cloves or 2 tbsp (20 g) paste
• Fresh rosemary, chopped 2 tbsp (4 g)
• Lemon zest 1 tbsp (6 g)
• Olive oil 2 tbsp (30 ml) or Dijon mustard 1 tbsp (15 ml) as binder

Equipment

• Charcoal smoker or kettle grill set for indirect heat
• Quality lump charcoal
• Red oak chunks or small splits
• Chimney starter
• Instant‑read thermometer
• Probe thermometer for the pit and meat
• Wire rack and sheet pan
• Butcher’s twine (for boneless)
• Long tongs and heat‑resistant gloves
• Carving knife and board

Wood

Red oak

Time & Temp

Time & Temp
Smoke temp: 250 °F (121 °C)
Target internal: 130 °F (54 °C)
Approx duration: 3.5 hours

Why Reverse Sear Works For Lamb Leg

Leg of lamb is lean, mildly gamey, and benefits from steady, gentle heat to keep the interior pink edge‑to‑edge. Reverse searing—smoking first at 250°F (121°C) then finishing over a ripping hot coal bed—builds smoke character and a deep crust without overcooking the exterior. It’s a controlled path to medium‑rare or medium with predictable carryover.

Choose and Trim the Leg

Use a 6–8 lb (2.7–3.6 kg) bone‑in leg for classic presentation and insulation around the joint, or a 5–6 lb (2.3–2.7 kg) boneless/netted leg for faster, more even cooking. Trim away hard surface fat and any thick silverskin; leave a thin, even 1/8 in (3 mm) fat cap for basting. If boneless, tie every 1.5–2 in (4–5 cm) so the roast is a uniform cylinder to promote even doneness.

Seasoning: Salt Early, Herbs Later

Lamb loves salt and aromatics. Salt the leg at least 12 and up to 36 hours before the cook for best diffusion: aim for 0.8–1.2% salt by meat weight. Keep herbal pastes for day‑of to avoid oxidized flavors. Right before it hits the pit, add pepper, garlic, rosemary, and a light oil or Dijon to help the crust set.

Fire Setup: 250°F (121°C) With Red Oak

Set your smoker or kettle for stable indirect heat at 250°F (121°C). Burn a clean bed of charcoal and feed with red oak splits or chunks; oak’s medium‑bold profile complements lamb without turning it acrid. Maintain thin blue smoke. A small water pan can help buffer temps but keep the pit dry enough to build bark. Plan enough lump charcoal to build a later coal bed for the sear.

Smoking Phase: Temps, Time, Targets

Place the lamb on at 250°F (121°C), fat up, probe the center away from bone. Expect roughly 30–40 minutes per pound, translating to about 2.5–4.5 hours depending on size and bone‑in vs boneless. For a reverse sear, pull from the smoker when internal reaches: 115–120°F (46–49°C) for rare, 120–125°F (49–52°C) for medium‑rare, or 130°F (54°C) for medium. The coal‑fire finish will add 8–15°F (4–8°C).

Brief Rest Before the Sear

Move the lamb to a wire rack over a sheet pan for 10–15 minutes while you build your coal bed. This air‑dry rest sheds surface moisture so the crust browns faster and keeps the interior juices calmer during the final blast.

Coal‑Fire Finish

Dump a full chimney of fully lit lump into your firebox or a coal ring under a low grate; add a second chimney if your pit allows. You want a fierce, even bed of glowing coals with minimal flame. Place the lamb about 2–3 in (5–8 cm) above the coals and sear, rolling and rotating every 45–90 seconds to avoid hot spots, 3–6 minutes total. Watch for flare‑ups; lift or momentarily move off the fire if fat ignites. Pull when the probe reads your final target: 125–130°F (52–54°C) for medium‑rare or 135°F (57°C) for medium. Expect 3–5°F (2–3°C) carryover during the final rest.

Doneness Guide and Checks

Lamb leg eats best medium‑rare to medium. Aim for 125–130°F (52–54°C) for rosy, juicy slices or 135°F (57°C) for a slightly firmer bite. Doneness should be confirmed with an accurate instant‑read thermometer in multiple spots; bone‑in roasts can read hotter near the femur. The surface should be well‑browned and aromatic, and juices should run lightly pink for medium‑rare or clearer for medium.

Slice and Serve

Rest the seared leg 15–20 minutes, tented loosely with foil. For bone‑in, cut along the femur to free large muscles, then slice across the grain into 1/4 in (6 mm) slices. For boneless, remove twine and slice across the grain. Keep slices warm and serve with simple accompaniments—lemon, olive oil, flaky salt, and a bright herb sauce—so the lamb stays the star.

Food Safety and Handling

Keep raw lamb separate from ready‑to‑eat items. Sanitize boards and knives, and wash hands after handling raw meat. Use clean trays for cooked meat; never return it to the raw pan. USDA recommends 145°F (63°C) final internal for whole cuts with a 3‑minute rest; many pitmasters choose medium‑rare (125–130°F/52–54°C) for quality—assess your risk tolerance. Chill leftovers to 40°F (4°C) within 2 hours; store 3–4 days and reheat to 165°F (74°C).

Troubleshooting

If smoke tastes bitter, your oak is smoldering; open vents and burn a smaller, cleaner fire. If the exterior is dark before internal temp is ready, reduce pit temp to 235°F (113°C) and avoid adding fresh wood for 30 minutes. If the coal finish flares, lift the meat off the grate for a moment or close the lid to starve oxygen. If you overshoot final temp, rest longer, slice slightly thinner, and finish with warm olive oil and lemon to reintroduce moisture.

Variations and Rub Options

Swap rosemary for thyme or oregano, add crushed fennel, or blend a paste with garlic, lemon zest, and anchovy for umami. A Greek‑leaning profile (oregano, garlic, lemon) or a North African touch (cumin, coriander, paprika) both play well with oak smoke. For a weeknight shortcut, go boneless/netted and target the same temps; it cooks faster and slices uniformly.

Notes

• Plan on 30–40 minutes per pound at 250°F (121°C); bone‑in runs longer.
• Pull from the smoker 8–15°F (4–8°C) below your desired final temp to allow for the coal finish and carryover.
• Keep smoke clean: thin, blue, and lightly aromatic. Heavy white smoke will turn lamb acrid.
• If using a kettle, bank coals to one side for the smoke phase, then dump a fresh chimney dead center for the finish.
• For a deeper crust, pat the surface dry before the coal sear and avoid sugary rubs.
• Serve with bright sauces like salsa verde, chimichurri, or lemon‑mint to cut the richness.