When it comes to leg of lamb, my tastes are fairly specific. After countless attempts and more than a couple of pretty obsessive experiments, I have determined that the ideal internal temperature is 140 to 145 degrees. Racks, of course, can be cooked to a somewhat lower temperature, 130 to 135 degrees, because they don’t have as much sinew and connective tissue.
So how do I explain that the best leg of lamb I’ve had lately is cooked to an internal temperature of 205 degrees?
Your first impulse is probably to laugh and say that this is impossible. Go ahead and get it over with; everyone else has. And while you’re in mid-scoff, let me add that to get to that temperature, you cook the leg more than six hours at 425 degrees.
This plainly and quite baldly flaunts everything we’ve been taught about cooking. That kind of heat is supposed to be reserved for quick cooking. Slow cooking requires much lower temperatures. And seven hours! That is pushing the limit of even the slowest of the slow.
In fact, I’ve broached this recipe on my chef’s chat group on the Internet and with several food scientists. Everyone’s first response has been that lamb at that temperature and time is quite impossible. Cook it like that, they say, and you’ll get something approaching a lamb briquette.
And yet I have what little evidence is left at home in the refrigerator. Six hours at 425 degrees, tightly sealed with wine and aromatics in a Dutch oven gives you a leg of lamb that is browned on the outside yet quite moist and juicy. It is a leg that has a very developed “lamby” flavor and meat that is quite literally falling off the bone (when I tried to push it aside the last time to keep it from sticking, the bone moved but the meat didn’t).
It is, quite simply, one of the best legs of lamb I’ve tasted, and so far nobody can tell me why it works. There are some interesting theories, though.
Daryl Tatum, a professor of animal science at Colorado State University, points out that a leg of lamb is very high in connective tissue (those stringy bits you find when eating rare leg of lamb). When cooked in a moist environment such as this one (with liquid, in a tightly covered Dutch oven), the collagen in the connective tissue is converted to gelatin very efficiently, keeping the meat moist.
Terry Dockerty, director of research information for the National Cattleman’s Beef Assn. (they used to do lamb too), theorizes that one possible explanation for the moistness of the meat would be that the muscle cell walls are made of connective tissue-like material and that even it may be gelatinizing.
Ray Field, a professor of meat science at the University of Wyoming, agrees. “The Dutch oven is holding the moisture in,” he says. “When you get the temperature up that high, the moisture is basically steam and it is penetrating the whole roast. It is going to gelatinize any connective tissue--between muscles, within muscles and next to the bone.
“It’s very similar to a pit barbecue, where you put the meat in a hole in the ground on top of two feet of hot coals and then seal the pit rapidly with at least a foot of dirt on top. The temperature for the first few hours is well over 400 degrees, and there is no place for that moisture to go. In 15 hours or so, it comes out very much like what you’re describing.”
One intriguing twist is that I also tried this recipe at 300 degrees--a much more traditional temperature for long cooking--and the result was much different. At 300 degrees, the lamb was more what you might expect from an overcooked braise--a tight, slightly dry meat texture that you could cut into slices. When cooked at the higher temperature, the meat was almost buttery and fell apart in moist chunks.
Janet Eastridge, a food technologist at the Department of Agriculture’s Meat Science Research Laboratory, has a couple of theories. When meat is cooked for a long time, the protein strands link up, tighten and squeeze out whatever moisture they contain. One possibility would be that the early high heat makes the protein strands brittle, preventing them from linking up later and drying out.
She also points out that one reason overcooked meat is dry and crumbly is the presence of enzymes within the meat that are activated within a fairly narrow temperature range and break down the protein structure. Cooked at 300 degrees, the lamb would stay in that temperature range much longer than at 425 degrees, where it would pass quickly through, not giving the enzymes enough time to do much damage.
However it works, it is apparently quite the thing in France these days. The mechanics of this recipe come from the fine cookbook writer Patricia Wells, who is also the restaurant critic at the International Herald-Tribune. She says it’s an old method, variously called gigot de sept heures or gigot a la cuillier (seven-hour lamb or lamb you can eat with a spoon). She got her recipe from the Parisian restaurant Ambassade d’Auvergne.
“In fact, the rage in Paris now is lamb that is first braised in liquid (usually wine, red or white) and then roasted,” she said in a recent e-mail. “In fact, I’ve come to prefer it over the modern and fashionable rare-cooked lamb.”
The impossible, it turns out, tastes pretty good.
It is much easier to carve a leg of lamb with the aitchbone or hipbone removed. But not every store has a butcher that can do this for you. It’s not hard to do yourself; you need only a small sharp knife. First, if the tailbone is present, cut the meat away from it and break it off. The hipbone that remains is a flat bone that forms a ball-and-socket joint with the leg. Cut the meat away down to the joint, then flex the joint and cut through the tendons holding the two together. Continue cutting the meat away from the hip until the bone comes free. Tie the end of the leg together with twine to keep it in a nice package for roasting.