It’s spring! The ice is melting, the trees are blossoming, the days are warming up, and the smoker is calling. I know I can smoke in the winter, but most of the time I tend to cook indoors. When things start to thaw, though, I get excited. It’s time to move my cooking outdoors! And spring cooking brings one thing in particular to mind for me: lamb. So we thought it would be great to cook up a smoked leg of lamb.
We’ve taken inspiration for this cook from Susie Bulloch of Hey Grill Hey. Susie is one of the top voices in BBQ today, and her thermal tips for cooking a sumptuous leg of lamb helped steer us in the right direction on this.
Smoking leg of lamb: temps for cooking and finishing
Smoker temp for smoking leg of lamb
At what temperature ought we to cook our leg of lamb? Low! Susie recommends 225°F (107°C) and you could go as high as 250°F (121°C), but don’t go any higher than that. We’ll keep it low and slow for two reasons: smoke and doneness.
First, smoke. Cooking at the lower temp allows our smoking wood to, well, smoke, not just light up like a match and burn. It’s hard to get good smoke flavor at temps higher than 250°F (121°C), so we’ll keep it low to maximize smokiness. The combination of the smoke flavor and the lamby, almost gamey flavor is quite wonderful. The smoke helps tame some of the wildness of the lamb without eliminating what makes it unique.
Second, doneness. Look, a leg of lamb isn’t cheap and you don’t want to risk overcooking it in a smoker that is too hot. Slow smoking decreases the temperature gradients in the meat and helps ensure more uniform doneness throughout. The slower cooking also gives the meat time to experience some enzymatic tenderization, which is important in a cut that can easily get tough.
Using Billows® BBQ Control Fan and a leave-in probe thermometer like Signals™ that can control it will help you keep your smoker at just the right temperature so you don’t have to stress about it during the cook.
Doneness temp for leg of lamb
Though doneness is a matter of taste, I usually like my leg of lamb cooked to about medium. With that in mind, we opted for a pull temp of 135°F (57°C). If you like your lamb to be pinker, lop off a few degrees and shoot for medium rare, 130–134°F (54–56°C). Smoking at the temperature we did means there is very little carryover cooking, even though this is a pretty bulky piece of meat, so the pull temp doesn’t need to be very far below your desired finish temp.
When the high-temp alarm sounds on your Signals, be sure to verify the doneness temp with Thermapen® ONE. (We do this not because we doubt the accuracy of Signals, but because we can’t know if Signals is taking the temperature in the exact right place. Pulling your Thermapen through the meat allows you to see the whole range of temperature gradients in the roast. If you see anything lower than your desired temp, adjust the location of your leave-in probe and continue cooking.)
Still, we didn’t want to overcook the lamb during the searing. (Yes, we are searing!) We let it sit in a cool breeze (a refrigerator also works, I guess) while we switched our cooker over from “smoker” to “grill” and stoked the fire. By the time the fire was hot enough to give the outside of the roast a sear, the lamb had vented some of its heat to the atmosphere. The cooled exterior creates a thermal barrier that the fire has to reheat before it can overcook the meat. The chill-step is great for getting a good crusty exterior without overcooking your roast.
Bone-in or boneless leg of lamb?
Whether to get bone-in or boneless leg of lamb is a matter of taste. But for this application, where we’re cooking slowly in a smoker, I prefer bonenless leg. They’re usually easier to find, and they’re easier to carve. Plus the ability to season inside the leg—where the bone used to be—allows you to pack more flavor into a large cut of meat.
Prepping lamb for smoking
Your lamb will most likely have a substantial fat cap on it. I recommend trimming that down fairly close to the meat. I want my lamb to taste like lamb, but the more fat you leave on it the lambier it will be.
That being said, cooking the lamb fat-side down will prevent a lot of that fat from coating the rest of the meat. It’s your call how much you want to trim.
A boneless leg of lamb is a little unwieldy and needs to be brought in line before you can smoke it successfully. Tying it into an even, cylindrical shape will help you get even doneness throughout. Use some butcher’s twine and tie it every two inches or so. Pull it tight, this thing needs to bend to your will!
Seasoning lamb for smoking
In this case, we have gone with a Moroccan flavor palate. All the lands around the Mediterranean have perfected their own style of cooking lamb, but this one seems to make the most sense to match flavor with the smoke. Slat, pepper, coarse chili powder, and harissa are all we use, but you could dress your lamb up however you like. Adding ras el hanout or garam masala would be great, but so would reverting to a classic lemon-herb seasoning (Susie uses lemon and mint, which will be totally delicious).
Whether you’re making a lamb roast for an Easter feast or just to celebrate the coming of spring (or just because you want something tasty any time of the year), smoking it is a great way to go. The smoky flavor, the beautiful color, the tender, juicy meat…they all come together to make for a roast that is far more than just adequate or traditional. They make for something wonderful. I hope you give this a try. It’s a great way to make lamb fresh and interesting, and the people you serve it to will love it.
Note: If you have a good meat slicer, do slice some of this up for cold cuts. Thin-sliced lamb sandwiches are phenomenally tasty.
Smoked leg of lamb, inspired by Susie Bulloch’s smoked lamb at HeyGrillHey.com
- Use Billows and Signals to preheat your smoker to 250°F (121°C). Add the smoking wood of your choice (cherry recommended).
- Trim the fatcap on the outside of the roast. Lamb fat carries a lot of the lamby flavor, so trim it as you like to get more or less of that taste.
- Season the lamb on the inside (where the bone used to be) with salt, pepper, and chili. Be very liberal with the salt and with the pepper.
- Score the fatcap with a sharp knife. Try not to cut into the meat.
- Season the leg all over with plenty of salt. Smear the surface all over with harissa. Sprinkle black pepper onto the harissa.
- Tie the leg up with butcher’s twine to make a uniform, even roast with no bits hanging off into space.
- Place the lamb on the smoker, fat-cap side down. (This will help protect the meat from any direct heat. If cooking in an offset smoker, place the lamb fat-side up.)
- Insert Signals’ probe into the very center of the meat. Set the high-temp alarm for 135°F (57°C) for medium doneness. Set it lower for medium rare.
- Close the lid and smoke the meat until the high-temp alarm sounds. (This may take 3–4 hours.)
- Verify the internal temp with Thermapen ONE.
Sear the roast
- If you are searing on the same unit you were smoking on, set it up for direct-heat cooking and heat it up. If you are using another grill to sear, preheat it about halfway before removing the meat from the smoker. You want to give it a chance to cool a little while the grill comes up to heat.
- Sear the leg of lamb on the grill over the hot flame. Rotate it every minute or so until there are some charred bits.
- Move the lamb to your cutting board.
- Slice it up and serve! This will be excellent alongside some grilled asparagus and buttered boiled new potatoes.
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